I am not sure if this is the right place or not, but I just installed the beta, 9.95.1, and I am experiencing the same issues with 5Ghz WiFi. All i am seeing is 2.4Ghz. To fix this issue, I need to edit the following file:
/storage/.config/modprobe.d/cfg80211.conf
and enter:
options cfg80211 ieee80211_regdom=US
I am not sure this is a bug or not, but just figured i would report it.