@hube2 update, I just copied the HTML being generated for these fields https://share.cleanshot.com/5cWX8j is over 134000 lines (see: https://share.cleanshot.com/W3uG3X) – could that be the main reason of the problem?
UPDATE:
I also see that the clone fields HTML is actually being generated on the page here: https://share.cleanshot.com/b0hqeA – is that normal? Isn’t there a way that this HTML is only generated when you actually add the layout?