It is kind of magic.
I will describe everything that happened with me and controller today.
Maybe, it will not be interesting for moderator but for those who just start to work with Aruba and does not know how everything is working i will tell something.
I decided to make full configuration again, so rebooted controller to default settings.
I turned on DHCP server on the controller and Control Plane Security. But my APs did not appear on the Provision list. I tried to switch off Control Plane Security or manually change certificate type and certificate state in the Whitelist. But nothing worked and I switched Control Plane Security on again. And still no result.
That i decided to check again DHCP config, and .... it was switched off. Someone may think that "What this stupid girl does, she just didn't switch on DHCP", but i am sure for 200% that i did. And now controller can see 2 from 3 of my APs.
Conclusion and questions:
1. I switch off and on Control Plane Security. This action switched DHCP off, so it is necessary switched DHCP on again.
2. From the previous configuration, on my computer, one of the AP still have static IP from another subnetwork. How can I tell AP to take IP from DHCP if I don't have it in Provision list?
Thank everyone who has read my answer to the end. Maybe It could help somebody sometimes. Because i have spend 1 day to get a result.
Best wishes,
Nadiia