@abundant-hair-58573 i am having the same issue, i have increase memory in resources, when i monitor cattle-agent it not utilising much but still rancher is sluggish.
Tried setting below vars in rancher pods per
https://github.com/rancher/rancher/issues/37350, but no luck.
--set 'extraEnv[0].name=CATTLE_SYNC_ONLY_CHANGED_OBJECTS' --set 'extraEnv[0].value=user,mgmt'
--set 'extraEnv[1].name=CATTLE_RESYNC_DEFAULT' --set-string extraEnv[1].value=20