Cheat Engine

[cyxap3k]

Weird behaviour: earlier I was able to find pointers throughout a pointerscan (I was comparing pointermaps + offset and there was a result). It 100% worked! Recently I restarted Windows and now I am able to find pointers as well (I've just tested it).
But it seems, there is a weird behaviour, because in last session (before restarting) after sometime, there are no pointers found. I don't know exactly what it depends on, but after some time pointers no more found: 0 results. I was wondering, what can cause such behaviour? (I relaunched Cheat Engine few time last session, maybe it is related to the problem.)

I thought, maybe there is a hook probem or handle issue. Maybe I should stop some process or smthg? Thanks for responses.
What should I be aware of?