AWS Client VPN re-authenticating while MacOS is asleep

We have a newly deployed AWS Client VPN, split tunnel using SAML federated authentication against Google. The setup is working reliably, but we've had several users (not all) on MacOS report 30-40 open chrome tabs after a 2 day weekend, all stating "Authentication details received, processing details. You may close this window at any time." This is normal activity for 1 tab to display this message after connecting and authenticating. Users have reported their laptops have been asleep during this period. We have the session timeout set to 12hrs. Do you have any advise on why this is happening and how to prevent it?