Hi there sorry for the inconvenience. There are several reasons why this is happening, such as:
If another user logs in, you will automatically be logged out.
Unstable network connection: Your account permissions will be checked before rendering begins to ensure that the assets are available and render in a stable network environment.
You may want to try these probable solutions:
Temporarily disable or enable VPN, see if disabling or enabling helps alleviate the situation.
Try transferring to another network if it is possible; this way, you will be able to compare if the previous network is causing the issue.