wifi – Fixed Channel : -1 ( in Scanning and deauth)

I was using Alfa awus1900 (Realtek 8814u) wifi adapter to test my wifi but from this point, it always shows fixed channel -1 while scanning a particular bssid and on deuath also and after using –ig to ignore -ve one also it is not effective. Sometimes it shows interface down while deauth. I tried reinstalling the driver and changing the driver but none work for me.. Can someone tell me how to fix fixed channel: -1?