Theme Update 5.2.1 to latest

I am a new administrator of a website with Enfold Theme v5.2.1 active with update name and API Key typed.
It says v5.2.1 and that I have the latest version and no update available.
I have read Your other thread about updating to the latest version, but the procedure with downloading and
installing a ZIP-file changes the format of the site and at the same time changes the default Logo to Enfold Logo.

When You later on restore the website the Enfold logo keeps staying on the site no matter what I do.
Luckily I had a snapshot of the server hosting the website and after restoring the snapshot the site was normal again.

In the backend of the website I under Enfold options I Reset all options.
After that I purchased a new license from Envato and created a new key to use for future updates.
Now the website indicates that there is a new update, but the same happens again when I update.

The website doesn’t look like it used to, but all the text is there and all links are working — however,
the layout looks completely wrong. I need a method to update the website without changing the visual appearance.
The website must look exactly as it did before we started the update.
Could it be that some plugins need to be updated first to be compatible with the latest version of the theme?

Can you please give me a complete guide to update from version 5.2.1 to the latest version
without the website changing visually?