I make a change on my page, click update, and get “updating failed.” I can fix the issue by installing Disable Gutenberg or Simple Editor plugins, however, this messes up the block editor in Shapely. Specifically, it screws up some YouTube video embeds that I had working perfectly up until now.
Solved. First I tried changing the permalinks per some internet advice, but no dice. Then I installed a duplicate post / page plugin and made dupes of the pages that weren’t updating. Then activated Disable Gutenberg and was able to update the duplicated pages, so I replaced the originals with those.