Dropbox and Google Drive Syncing Issues

I have a 2018 MacBook Pro running Big Sur. About a week ago I noticed that my Dropbox files had not been synced in a couple of weeks. I also noticed that Google Drive syncs had stalled as well. I tried restarting, etc., and eventually reset by router. That got Dropbox and eventually Google Drive to complete their syncs, but the issue reoccured as soon as I added or updates files. Since then I've tried everything I can think of. I've updated Google Drive, reinstalled Dropbox, delinked my MacBook Pro (2018), all to no avail. The only way I can restart a stalled sync is when I switch to a different network, and even that is only temporary. Usually it takes a network with a different router, but again, that is only a temporary relief. Next time either Dropbox or Google Drive syncs, the process stalls. Been scratching my head on this one. Does anyone have any ideas?