Thank you for
reaching out on the community and telling us about your issue. How long have you been having this issue? Has it been since the most recent patch or further back? You're able to sync without it so it's entirely the cloud like you said.
Could we try one thing. Go across the top to edit -> Preferences -> Mobile and web. Turn the sync off and then on. This will have it do the initial sync again but I'm wondering if it will still crash while not updating with the accounts. If it doesn't try doing an OSU again and see if we're crashing still.
Another thing to check for is trying individual accounts to see if there's one in particular that's giving us trouble. In the same preferences menu you'll have the option to choose the accounts.
Please let us know how it goes!