seems like I found something that could be helpful to Mikrotik: wireless AP Sparklan 1590, 500m distance, -55dB signal, 2472Mhz (13th channel), no problems with 2.8.27. After upgrade to 2.9.7, prism stopped working. Sparklan is Access Point because it is its natural mode, Prism card is mode=station because it is its natural mode. ATX computer, configuration doesn’t matter, stable platform. Problem is in software.
We tried everything, really everything. Guess what helped!
We changed frequency-mode from manual-txpower to regulatory-domain. No help. We set country= from “no_country_set” to my country. Nothing. Everything started working when we set frequency from 2472 taken from previous version after upgrade. As soon as we manually set frequency from 2472 to something else, client is connecting and passing data. When we changed back to 2472, immediately prism was disconnected and didn’t connect back. Change that again to whatever channel, voila you have connection again. I understand that client’s setting has no effect as clients “adapts” to channel used on AP it is connecting to, but this is our observation and we have huge experience (!!!) with MT. This problem is 100% reproducible for us and occurs after EACH REBOOT.
What is the most strange thing : after two or three changes back and forth from/to channel 13 (freq=2472), we can have freq=2472 and it works!! And yes, this is also 100% reproducible.
Is this good enough for Mikrotik to analyze? Do you need any further information?