I have been having the same issue today. Unfortunately, my option to revert to an older version is missing. However, this evening the Page Builder seems to be working again so I can rebuild my page, except that none of my html will work properly. It’s like the tags are being ignored, but only some of them…
Sometimes it adds an rn to the ends of the lines when I save. If I remove all the line breaks the “rn”‘s don’t appear, but the code still is not working. It makes me wonder if there are “rn”‘s in the code I can’t see causing the problems?
I have a copy of this page (with a few small differences) that I haven’t made any changes to on the same site, and it is working, so I know it’s not a problem with my html code.