Have you tried clearing the Teams cache? That should work when you have this error:
https://learn.microsoft.com/en-us/microsoftteams/troubleshoot/teams-administration/clear-teams-cache
For more troubleshooting info on 404 errors you can also try this link: https://learn.microsoft.com/en-us/sharepoint/troubleshoot/administration/error-404-onedrive-sharepoint