Any helpful hints to resetting my email on the PC webpage portion of the Gatherer?

Ok I switched over to Dropbox, but I am a big dummie lol. I do have two emails with Dropbox and i think my pc has the wrong one LOL. I swear this will be the last time, i tried deleting the cache and data but it doesnt let me sign back in, so im at a loss

I reinstalled the mobile app, and i put in the right email lol, but sadly its not syncing the info with my PC. I added cards from my phone, and uploaded it, then downloaded to my PC, and it says download is successful, but the cards never update. Does Dropbox work better?

I completely restarted the app and the webpage restarted too, so I think it all good. I connected my Onedrive to both and they are synced well, thank you! I think there was an issue when i added things to both versions and didnt back it up, it had a bunch a different save. What can I do with Users to separate my PC and mobile versions?