[hAP ax3] Wifi 5 Ghz channel are weak constantly dropped

Thank you for your thorough explanation. I ran the command and here is the output

/interface/wifi/radio/reg-info number=0 country=Denmark
  ranges: 2402-2482/20
          5170-5250/23/indoor
          5250-5330/23/indoor/dfs
          5490-5730/30/dfs
          5735-5875/14

I have read and understood your comment, but tbh, I am not sure how can I apply it. Do you have some specific recommendation for me what to try next?