When you log into EVE you are given a session ID and keep it for as long as your still connected; all your scanning results are connected to your session ID. You disconnect/logoff, you lose all your scanning data as when you are back online again you’d be in a new session. It sucks I know but not much you can do about it. If you’d like you can drop a suggestion in the Little things/small QoL thread
Sounds like Trip-Wire or similar tools it what you’re looking for, here’s a link for you 