I just upgraded my Mikrotik box to 2.9.22 and seemed to have lost the frequencies 2467 and 2462 (Channel 12 & 13) on 2.4ghz Wireless Prism Card. Does Mikrotik 2.9 not supported those frequencies?
Perhaps check the country code you are using to mnake sure is one to support 12 & 13
also from which version did you upgrade? 2.8? then you must set wireless card’s mode to regulatory-domain and set in what country you live in.