Problem with wpa_supplicant in Buster on a Raspberry Pi 4B

[Freek de Kruijf <f.de.kruijf@gmail.com>]

After analyzing an unreliable WiFi connection I did test the wpa_supplicant 
utility on that connection.
So I used the command "wpa_supplicant -c<wpa_supplicant_config> -iwlan0 -d" to 
see what was wrong.
It appeared that the SSID of the AP I want to connect to was entered in the 
blacklist, later removed, retried again, etc.
At a certain moment it succeeded, but a little while later the status was 
again DISACCOCIATED.

Anybody experiencing the same?
Is there a workaround? 

-- 
fr.gr.

Freek de Kruijf