Thank you so much, Eric! I've been meaning to reply for days but kinda wanted to try solving with the mount out on a clear night and finally had one - what you suggested totally did the trick! How on earth did you figure that out?? Is this a step everyone has to perform after new installation? Thank you very, very much.

On a related note I still get a message (screenshot attached) that "Index files index-4206 to index-4211 are missing" in spite of them having a check mark on the index files list in Ekos. Solving (polar and otherwise) seems to work fine, although I always perform the GOTO solving in the same spot to the west northwest, so maybe the missing files are for a different part of the sky. Or does the full message mean that if I tried solving Online instead of Offline, that for some reason it would fail..? Either way, should I try downloading these "missing" index files and placing them in the new "~/.local/share/kstars/astrometry" folder to stop the error message?