Why is this hapening?
Signal is -65, Noise -91 (one side) -101 (the other side), SN 23 and 35. Sometimes wireless uptime is up to 2-3 days.

Noise. It's not being detected by the "noise" measurement made by the radio card. You would probably see it with a proper spectrum analyzer. It is possible that something in the system has failed or is failing (radio card, pigtail, antenna, cable, etc.) but it's likely just noise.

Same in 5 Ghz and there is nothing here(when i scan) in 5Ghz. I understand in 2.4Ghz, but what about 5Ghz?

The scan and freq use tools in Mikrotik only show 802.11 traffic. These tools are not measuring raw energy levels received by the radio. That being said, I assume you tried a number of different 5G channels and had the same problem. If so, then you probably have a problem elsewhere and you need to start changing variables one-at-a-time to find it.

same to me

RB333 + XR5 + 24db flat ===== RB411 + XR5 + 17db sector