We are using snooper tool via telnet. If I run command /interface wireless snooper snoop wlan1 and than press button s for switch snooper list to station list, I am not able to see frequencies used by listed stations. I think, that this is small bug, which is related with changes in presentation of frequencies (ie. 5700/20/an, in older RouterOS versions was ie. 5700MHz),
Many thanks for fixed this bug.