SharePoint Migration Manager keeps disconnecting after a few hours

Hello, we have the problem that we install the SharePoint Migrations Manager and we log in with a SharePoint Admin account, then we only have a connection for a few hours. But after some time the migration agent disconnects. So we can't plan and implement migrations. We suspect that it is related to an expired token. We have also tried to deactivate MFA for the SP Admin account. Do you have any idea what this could be or what settings need to be made to have the migration manager permanently connected.