ok – if you like to have on default a sidebar header – and on homepage only the header top position.
( for that scenario we need than a bit different css too if you like to have slide-out from left to right)

1 set your enfold child to header top and make all your decisions you like to have for that header ( height, logo left or right, navigation position, shrink or not, etc pp )

2 Go to your homepage editor and make your decision there – f.e. if it should have transparency etc.

3 Look now to your homepage with dev tools of your browser. Note your ID of that page and look what classes are set on #header
e.g.: ( all_colors header_color light_bg_color av_header_top av_logo_right av_main_nav_header av_menu_left av_custom av_header_sticky av_header_shrinking av_header_stretch av_mobile_menu_tablet av_header_searchicon av_header_unstick_top_disabled av_bottom_nav_disabled av_header_border_disabled )

4 now switch back to your header left position.

put this to your child-theme functions.php:

(remove options you do not need – or replace – f.e. header_size and header_custom_size and replace by header_size: ‘slim’ / or large )
you can find those corresponding header settings in : avia_header.php

function av_change_header_style($header){
  if(is_page(array( 17, 123456))){ 
    $header['header_position']    = "header_top";
    $header['header_layout']      = 'logo_right main_nav_header menu_left';
    $header['header_size']        = 'custom';
    $header['header_custom_size'] =  140;
    $header['header_shrinking']   = 'header_shrinking';
    $header['header_sticky']      = 'header_sticky';
    $header['header_unstick_top']   = 'header_unstick_top';
    $header['header_stretch']     = 'header_stretch';
    $header['header_transparency']  = 'header_transparency header_glassy';

    $header['header_class'] = " all_colors header_color light_bg_color av_header_top av_logo_right av_main_nav_header av_menu_left av_custom av_header_sticky av_header_shrinking av_header_stretch av_mobile_menu_tablet av_header_searchicon av_header_unstick_top_disabled av_bottom_nav_disabled av_header_border_disabled";
  }
  return $header; 
}
add_filter('avf_header_setting_filter','av_change_header_style');

here in this example there are two pages (ID’s) replaced with that different layout – adjust to your home page ID
this filter has a lot more options. Enter on $header['header_class'] your noted classes from point 3.

see example page: https://clean.webers-testseite.de/

I have now updated all of my installations to PHP 8.3 or higher. Some of my customer providers already offer PHP 8.4. I have never had any problems switching. Therefore, I assume there is high compatibility with current PHP versions. My overloaded test site runs under PHP 8.4.7. For example, the child-theme functions.php has over 5,000 lines, and the quick CSS is already over 9,700 lines long. (webers-testseite.de).

Why don’t you try going back to smaller PHP versions one at a time? It may take a while for this to take effect. Then, see if your installation works with your provider.

if you follow that little link on enfold options:
(these two cards icon)

you will see on that wiki page a good overview; and in detail a browser support. Best Format seems to be png.
a svg has a bad support.

you can manually add them if you put this to your child-theme functions.php:

function add_icons_to_head(){
?>
  <link rel="icon" type="image/png" href="/wp-content/uploads/icons/your-favicon-image.png">
  <link rel="apple-touch-icon" type="image/png" href="/wp-content/uploads/icons/your-apple-touch-icon.png">
<?php
}
add_action('wp_head', 'add_icons_to_head');

You are free to select the names and paths of your PNGs.

By the way, if you have two date pickers, one for the start date and one for the end date, you can restrict the second date picker so that it only allows dates that are later. For example, we can also remove weekends from the selection.

here in my example the minDate/maxDate are relative Values by +7 Days and +12 Month:

function my_datepicker_limits() {
?>
<script type="text/javascript">
window.addEventListener("DOMContentLoaded", function () { 
(function($) { 
    setTimeout(function() {
        var $allDatepickers = $('.avia_datepicker');

        // Let's assume that the first avia_datepicker found is the start date
        var $startDateField = $allDatepickers.eq(0);
        // and the second avia_datepicker found the end date
        var $endDateField = $allDatepickers.eq(1);

        // Check whether we have found at least two datepicker fields
        if ($startDateField.length === 0 || $endDateField.length === 0) {
            console.warn('Could not find both Start and End datepicker fields. Ensure they are the first two .avia_datepicker elements.');
            return; // Exit script if not enough fields are found
        }

        // Find the container of the end date field (the <p> element in your structure)
        // This is the parent tag of the input field that also contains the label.
        var $endDateFieldContainer = $endDateField.parent('p.form_element');

        // Fallback if the container is not the <p> tag or is not found
        if (!$endDateFieldContainer.length) {
            $endDateFieldContainer = $endDateField; // Then we only hide the input field itself
        }

        function updateEndDatepickerState() {
            var selectedStartDate = $startDateField.datepicker('getDate');
            

            if (selectedStartDate) {
                // Optional: Add one day to ensure that the end date is at least one day after the start date.
                // then remove the backslashes of the next line
                // selectedStartDate.setDate(selectedStartDate.getDate() + 1);
              
                // If a start date is selected, display the end date field
                $endDateFieldContainer.css('display', 'block'); // Verwendet 'block', da <p> ein Block-Element ist

                $endDateField.datepicker('option', 'minDate', selectedStartDate);

                // Optional: Make sure that the end date is not before the start date.
                var currentEndDate = $endDateField.datepicker('getDate');
                if (currentEndDate && currentEndDate < selectedStartDate) {
                    $endDateField.datepicker('setDate', selectedStartDate);
                }

            } else {
                // If no start date is selected, hide the end date field
                $endDateFieldContainer.css('display', 'none');

                // Reset minDate of the end date date picker (e.g. to “today”)
                $endDateField.datepicker('option', 'minDate', 0);
            }
        }

        if ($startDateField.data('datepicker')) {
            $startDateField.datepicker('option', {
                beforeShowDay: $.datepicker.noWeekends,
                minDate: "+7d", 
                maxDate: "+12m",
                onSelect: function(dateText, inst) {
                    // Update the state when a date is selected
                    updateEndDatepickerState();
                },
                onClose: function(dateText, inst) {
                    // Update the state even when closing the data picker (for robustness)
                    updateEndDatepickerState();
                }
            });
        }

        if ($endDateField.data('datepicker')) {
            $endDateField.datepicker('option', {
                // beforeShowDay: $.datepicker.noWeekends,
                minDate: 0,
                maxDate: "+12m"
            });
        }

        // Execute the function once when loading the page to set the initial state
        updateEndDatepickerState();

    }, 500);
}(jQuery));
});
</script>
<?php
}
add_action('wp_footer', 'my_datepicker_limits', 20);

see: https://webers-testseite.de/datepicker/

Edit here – because topic is closed:
This was also only intended as additional information. It is in case someone lands here via the search. They may have exactly this request.