Why is data transfer interrupted when the link is stable?

Question

WiFi

Good afternoon friends!
Help advice, because I do not know where to dig.
A bunch of Mikrotik GrooveA 52 ac b (Access Point) and 3 pcs Mikrotik SXT Lite2 (Clients) worked well and for a long time, but for some unknown reason, the data transfer began to be interrupted :( The radio link does not break
at the same time.

What could it be?
UPD: It has arrived in the evening, and everything almost returned to normal.There are no numerous gaps on the graphs.(in the morning the graph was like a saw) But if they are, then already on the AP and on the client.The

problem starts from 8 am somewhere until 17... Very interesting. I
went to the place. (It's a pity not during problems) Here is such a picture on the air:

Everything was tuned to a frequency of 2422. I retuned to 2447, I'll watch tomorrow.

Answer 1

Judging by schedules clients fall off. Does the dump go immediately to 3 clients at once or to one?
As options for a possible solution:
1) Clean the logs and counters (very rarely, but it happens that the problem lies here)
2) If the channel and frequency are not hard-set, then set it. Maybe the AP or the clients are trying to jump to a less noisy channel so try to hardcode the same frequency and channel everywhere.
3) Try to monitor the signal from the AP at the moments of dips, if the signal from it disappears. Perhaps the problem is iron and the radio module began to fail.

Answer 2

Alternatively, try using nstream instead of nv2. Under certain conditions, these protocols can give radically different results and nv2 does not always win.