Don’t know what SOPE stands for, but it is a dependency of SOGo.
When removing modules from dashboard in most cases only the module is removed but not the underlying/related software. If you search the forum you’ll find past discussions about it.
Here is a more complete SOGo removal (but when removing things it’s always good to proceed with extra care):
AFAIK, the loop is done when there’s a sync problem, like a wrong entry (ex. starting date newer than ending date, etc.).
I guess a troubleshooting step would have been to identify/locate the message by the reported id and analyse it, but I do not know how it is done.
Glad it is (mostly) working.