Hi Ismael! Below is the response from WooCommerce support regarding your request:

—–
So it looks like the theme has added an overflow hidden rule which is restricting the calendar displaying which is why it is cut off. To get around this you could ask your theme developer to remove that or override it yourself using this CSS code added to the theme stylesheet or via the Additional CSS section of the Customizer (I did try to access that myself but there is an error when you try to access the page):

.single-product form.cart {
overflow: visible !important;
}

The above alone won’t be quite enough however as when you apply this it looks like they have a high z-index on the product tabs for some reason so they will overlap the calendar too, again get them to fix that or use this code to override it:

#top div.product .woocommerce-tabs ul.tabs {
z-index: 0 !important;
}
—–
Hope this is helpful! Please let us know if you have any more questions or if there’s anything else you need to help us get this issue resolved.

Hi Yigit! Just following up on this ticket. Let me know if there’s anything else you need to help us resolve this issue. Looking forward to your response!

Unfortunately, this issue has not been resolved yet. We are still receiving the same fatal error when trying to add the Masonry element to a page / post. I tried the band-aid solution on this thread that seems to be similar, but it did not work:
– https://kriesi.at/support/topic/4-1-2-bug-masonryblogposts-element-needs-woocommerce-functions/

John – Please let us know if there’s anything else you need to help us resolve this issue. Thanks!

Very much appreciated, Josue!

Hi Andy, this issue began before I installed the Child theme. That was just an experiment I tried after the fact. However, I was able to get GYM working perfectly on DreamHost, which means this is a Pantheon problem. I will proceed to build this site on DreamHost but wanted to make you aware of my findings. Thanks again!