All right, will do! Thank you for your help.
Thank you for your reply!
Disabling plugins/switching themes didn’t help. I did notice one additional thing though – on every page in my wp-admin I’m getting this message:
Action Scheduler: 4 past-due actions found; something may be wrong. Read documentation »
Those look like Surecart jobs to sync products (they were all called “surecart/sync/product”), and so I ran them manually, but unfortunately the content designer is still not loading for these older products after these jobs were completed.
(Btw, that action scheduler message has been there for a while, but it lacked any context as to which plugin it’s related so I wasn’t sure what do about it.)