There was an error with Spam functionality

I’m trying to get setup with runbox but all 3,300+ emails in the spam folder can’t be moved out because I get an error “There was an error with Spam functionality.”.

I’ve turned it for now but how can I get these messages moved so they aren’t deleted?
I even tried within Runbox 6 and there wasn’t a way to move spam messages, unless I didn’t see it.

Also - I only have access to POP for my current email host, the emails being retrieved are using the current date/time instead of the original send date/time. How do I fix that?

Also 2 - I added filters after I setup my POP, how do I force filtering after the fact?