Activation: (wifi) association took too long, failing activation on Ubuntu 20.04 LTS

[w8970]

I build and install driver 5.8.7.1 on Ubuntu 20.04 with Linux 5.11.0-25-generic according https://github.com/cilynx/rtl88x2bu#dkms-installation successfully.

The WiFi scan works, other WiFi networks will be listed, but connection doesn't work. No matter if I try to connect to open WiFis or WPA2 secured ones. Same issue were present with driver version 5.6.1.

Here some related prints from the syslog:
Aug 12 19:30:51 luzifer-ub20-04lts kernel: [ 1.378883] usb 1-12: New USB device found, idVendor=0bda, idProduct=b812, bcdDevice= 2.10
Aug 12 19:30:51 luzifer-ub20-04lts kernel: [ 1.378891] usb 1-12: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Aug 12 19:30:51 luzifer-ub20-04lts kernel: [ 1.378894] usb 1-12: Product: 802.11ac NIC
Aug 12 19:30:51 luzifer-ub20-04lts kernel: [ 1.378897] usb 1-12: Manufacturer: Realtek
Aug 12 19:30:51 luzifer-ub20-04lts kernel: [ 1.378900] usb 1-12: SerialNumber: 123456
...
Aug 12 19:31:02 luzifer-ub20-04lts NetworkManager[1448]: [1628789462.8949] device (wlx1cbfce383270): driver supports Access Point (AP) mode
Aug 12 19:31:02 luzifer-ub20-04lts NetworkManager[1448]: [1628789462.8960] manager: (wlx1cbfce383270): new 802.11 Wi-Fi device (/org/freedesktop/NetworkManager/Devices/3)
Aug 12 19:31:02 luzifer-ub20-04lts NetworkManager[1448]: [1628789462.8979] device (wlx1cbfce383270): state change: unmanaged -> unavailable (reason 'managed', sys-iface-state:
...
Aug 12 19:31:33 luzifer-ub20-04lts wpa_supplicant[1473]: wlx1cbfce383270: CTRL-EVENT-REGDOM-CHANGE init=BEACON_HINT type=UNKNOWN
...
Aug 12 19:33:58 luzifer-ub20-04lts NetworkManager[1448]: [1628789638.1001] device (wlx1cbfce383270): Activation: starting connection 'Freifunk Freital [1296]' (990b76d8-dc55-4fb1-ba04-d6a6797c7719)
Aug 12 19:33:58 luzifer-ub20-04lts NetworkManager[1448]: [1628789638.1003] audit: op="connection-activate" uuid="990b76d8-dc55-4fb1-ba04-d6a6797c7719" name="Freifunk Freital [1296]" pid=3477 uid=1000 result="success"
Aug 12 19:33:58 luzifer-ub20-04lts NetworkManager[1448]: [1628789638.1005] device (wlx1cbfce383270): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
Aug 12 19:33:58 luzifer-ub20-04lts NetworkManager[1448]: [1628789638.1013] manager: NetworkManager state is now CONNECTING
Aug 12 19:33:58 luzifer-ub20-04lts NetworkManager[1448]: [1628789638.1023] device (wlx1cbfce383270): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
Aug 12 19:33:59 luzifer-ub20-04lts kernel: [ 228.757466] start_addr=(0x20000), end_addr=(0x40000), buffer_size=(0x20000), smp_number_max=(16384)
Aug 12 19:34:00 luzifer-ub20-04lts NetworkManager[1448]: [1628789640.1702] device (wlx1cbfce383270): Activation: (wifi) connection 'Freifunk Freital [1296]' requires no security. No secrets needed.
Aug 12 19:34:00 luzifer-ub20-04lts NetworkManager[1448]: [1628789640.1703] Config: added 'ssid' value 'Freifunk Freital [1296]'
Aug 12 19:34:00 luzifer-ub20-04lts NetworkManager[1448]: [1628789640.1703] Config: added 'scan_ssid' value '1'
Aug 12 19:34:00 luzifer-ub20-04lts NetworkManager[1448]: [1628789640.1704] Config: added 'bgscan' value 'simple:30:-70:86400'
Aug 12 19:34:00 luzifer-ub20-04lts NetworkManager[1448]: [1628789640.1704] Config: added 'key_mgmt' value 'NONE'
...
Aug 12 19:34:21 luzifer-ub20-04lts NetworkManager[1448]: [1628789661.0986] device (wlx1cbfce383270): supplicant interface state: disconnected -> scanning
Aug 12 19:34:21 luzifer-ub20-04lts NetworkManager[1448]: [1628789661.0987] device (p2p-dev-wlx1cbfce383270): supplicant management interface state: disconnected -> scanning
Aug 12 19:34:25 luzifer-ub20-04lts NetworkManager[1448]: [1628789665.2552] device (wlx1cbfce383270): Activation: (wifi) association took too long, failing activation
Aug 12 19:34:25 luzifer-ub20-04lts NetworkManager[1448]: [1628789665.2553] device (wlx1cbfce383270): state change: config -> failed (reason 'ssid-not-found', sys-iface-state: 'managed')
Aug 12 19:34:25 luzifer-ub20-04lts NetworkManager[1448]: [1628789665.2558] manager: NetworkManager state is now DISCONNECTED
Aug 12 19:34:25 luzifer-ub20-04lts NetworkManager[1448]: [1628789665.2572] device (wlx1cbfce383270): Activation: failed for connection 'Freifunk Freital [1296]'
Aug 12 19:34:25 luzifer-ub20-04lts NetworkManager[1448]: [1628789665.2577] device (wlx1cbfce383270): state change: failed -> disconnected (reason 'none', sys-iface-state: 'managed')
Aug 12 19:34:25 luzifer-ub20-04lts NetworkManager[1448]: [1628789665.2657] device (wlx1cbfce383270): supplicant interface state: scanning -> disconnected
Aug 12 19:34:25 luzifer-ub20-04lts NetworkManager[1448]: [1628789665.2658] device (p2p-dev-wlx1cbfce383270): supplicant management interface state: scanning -> disconnected

What can I do to find the issue?

Should I provide more information?

Thanks in advance,
Erik