Hello,
After updating to Wordpress 5.5.3 I have noticed on one of my sites that when I am in the pro builder editing a page and I try to save, sometimes I get a message saying the save failed and when I press on back to Dashboard after editing the page in the builder I get a white screen with the notice that “There has been a critical error on your website”. I can press back and then press on dashboard again and it finally goes there properly.