I'm having this problem where it usually logs me out within a minute or two of logging in. It happens on my phone and on Windows, with 3 different browsers. Also on the phone, every 2 or 3 days it acts like biometrics were never set up, and I have to set them up again. The account and browser extension settings are both set to stay logged in. This behavior started about 3 weeks ago.
Hi
Welcome to the LastPass Community.
About your issue, the best practice is to enable passwordless with biometrics, or set the privacy settings to never log out.
Outlined in this support articleUse passwordless login for vault on mobile
HildaC