This is the first case I have run into this issue and these are the circumstances that I have done to create this problem.
I have a required field that is hidden conditionally, typically if the field is hidden and is empty, that is not a problem. But now that I have tried to do this inside of a Flexible Content area, the hidden fields won’t let me update the page if it is empty. But if i toggle the condition (True/False) and show the hidden field and then toggle it back off, I can update the page with the required field still being empty.
I have thrown together a quick video with some dummy fields to show the problem: https://youtu.be/jdwA2suQQEw
I am not sure which forum to put this in since it is Backend, ACFPro, Flexible Content, and a Bug all in one.