same issue here on build 11.1.10.5 on-prem, i leave about 10 tabs open on my IT jumpbox, as I have several software tabs open so i can review upgrades/obsolete installs to be targeted by my global team & also individual asset tabs for systems we are working on/installing new apps. until recently i was never signed out for inactivity. now its just getting irritating, as if you are signed out, all your tabs revert to the main sign in page!! looks like its if you don't do anything in over 24 hours.
Where is this setting for inactivity, so it can be switched off??