Alfa Awus036NH

Hi guys, i'm asking to myself why my ALFA AWUS036NH isn't working like in the past.

My os is Kali linux 2019.4 all updated , before when i started a scan with kismet my network adapted reached connections and devices of all type in a range of 150 meters away.

Now it is not detecting well, before i used to find immediatedly 100+ devices now i can't even find 50 devices in 10 seconds..

What is the explaination to this? i don't find nothing online, or maybe i don't search the appropriate terms.