In a site with ACF custom fields in various templates, we experience a strange limitation only with certain WYSIWYG fields when editing, between visual mode and text mode on the field.
The admin can select a certain part of the visual mode content in the WYSIWYG field and switch to text mode to see that same content highlighted, in most cases.
But in only certain fields, this does not work. Unfortunately it is an issue on the ones with lengthy content in them, so if the admin needs to select a sentence and work on the div code or insert some corrections via text mode, they cannot do this easily. Each time they try to select the text tab, it just scrolls back up to the top of the content and without any highlighted section she was working with. So she has to manually scroll down and hunt for the content she wanted to edit again.
I would have normally dismissed this assuming it was not a supported feature, but it works just fine in the convenient way (sort of bookmarking where you were editing within the field) on all other fields except for a few of them.
What could the cause be? Is there any known issue that prevents the switch from visual to text mode from working consistently to highlight where you were editing inside that field?