I don't know what impact the server modifications will have in the short term, or if browser issues or caches affect things. There are so many moving parts. I would just say hang in there for 24 hours and see if things smooth themselves out.
I was attempting to respond to this - and although the notification error disappeared , the whole forum froze out for about ten minutes; View attachment 89808
I've been getting those bands and the same colour over the top of the toolbar of the page.
However had it tonight again but the post still was saved.? Seeing it when I save the post, but very quick now.
I've updated a security setting on my server to see if it will solve the new Oops! issues. It should do the trick. Let me know if certain code still triggers the error or not.