Is it normal that several processes are started several times?:
I do currently have the problem that playback sometimes starts and then after some time it stops. But I’m not sure if this is related to my Wifi.
Did you consider iwd as a replacement for wpa_supplicant? The advantage in my case would be that iwd allows much better control over which band (2.4, 5 GHz) should be used (all options to control the behavior don’t seem to work for wpa_supplicant).