Hello,
This is a known issue. Many users seem to have this issue recently. Microsoft is still investigating this issue. The current workaround is published here: https://support.microsoft.com/office/users-get-errors-0x800ccc0e-0x800ccc0f-synchronizing-gmail-and-yahoo-accounts-in-classic-outlook-e5a7b684-7c5c-4848-ab2d-d48291451f67
You can also use New Outlook for now, that I know it is working fine.