WiFi power output issues on WRT1200AC (V1)

I am having some issues with the WiFi power output on my WRT1200AC (V1).
Mainly the 2.4GHz output power/signal strength is much lower than it should be, being both beaten by the 5Ghz signal by a large margin (7-10dB) and even only being around the strength of a 20dBm (with 3dBi antenna) ATH9k USB adaptor plugged into it (bar having the output power set to 30dBm or higher).

Not only that, but the power output settings also don't seem to work, with the same signal strength on both (inbuilt) radios not changing no matter what setting the output power is set at.

I do manage to get something alone the lines of a 10dB gain on 2.4Ghz if I switch the WiFi region to an other region with the same power limits (like PA), which seems to suggest that the power table for my region (AU) is broken, but that does not help with the output power setting not working.