I'm also seeing this. I can also see the Index refresh about once every 5 seconds or so.
I also see an error dialog when trying to backup:
"SQLite Error 1 - no such collation sequence RMNOCASE."
I used all the DB tools to clean up the DB (compact, Clean Phantom records, etc) and it reported no errors.
This is pretty recent behavior. Happens when signed in or not to FamilySearch. May be related to Ancestry TreeShare. Seems to be hung trying to sign in to Ancestry. Trying to close the Ancestry Sign-In dialog throws the pending Operations dialog. I can sign in to Ancestry on the web just fine.
RM v 7.5.7