Raspberry PI 4 & Kali Linux airodump-ng question

Hey all!

I have been practicing an Ethical Hacking course on my WEP wifi in order to learn. I am extremely interesting in PEN Testing and hope I can get certified one day but keep running into a snag here and there.

For some reason when I run sudo airodump-ng wlan0mon I see information about my wifi router and connections for about 30 seconds. Afterwards all the info disappears. If I do CTRL-C to kill/quit and restart it I get no information and it the terminal seems very slow. If anyone has any ideas I will try it and get back to you!

Commands:

sudo iwconfig wlan0 power off (turn off power management mode)

sudo airmon-ng check kill

sudo airmon-ng start wlan0

sudo airodump-ng wlan0mon

#It runs for about 30 seconds before stopping and all information disappears.

#killed the process with CTRL-C and try to start it again but get the blank screen.

Not sure why this is happening or how to fix...

I am not using an external wifi adapter I am using the built in PI 4 wifi since it has monitoring mode and I think injecting (could be wrong)

If I reboot the PI 4 and retype everything I can get it to run for another 30 seconds. But I HAVE to reboot for it to work again.

Hardware: Raspberry Pi 4 B
OS: Kali Linux 64 bit 2020.3 for compatible with Pi 4

Thanks, Karp