couldn't setup /dev/mmd_* devices

[rcreate]

I'm using HmIP-RFUSB on a Raspi4b on debian 11 with home assistant supervised installation.
On my board I added raspbee2 on GPIO and a CC1101 module on SPI.
So far all works fine.

I plugged in HmIP RFUSB using 2m cable to USB2 port, installed the addon and tried to start it. I get the errors in the log below. I checked all things chatGPT had suggested:

• added eq3_char_loop to /etc/modules-load.d/...
• modprobe eq3_char_loop before start to be sure
• stopped homegear(-gateway) and deconz service temporarily
• added KERNEL=="eq3loop", MODE="0666" to /etc/udev/rules.d/99-eq3loop.rules

I checked devices on host:

crw-rw-rw-  1 root root    239,   0 18. Apr 22:48 eq3loop
crw-------  1 root root    235,   0 25. Aug 2024  raw-uart
# after container started
crw-rw----  1 root dialout 239,   2 18. Apr 22:49 mmd_bidcos
crw-rw----  1 root dialout 239,   1 18. Apr 22:49 mmd_hmip

I've no idea what else to do. Some days ago, I experimented also by installing debmatic with debmatic I was able to pair a hmip device. Sometimes between, I also managed to get raspberrymatic started with HmIP and HM-Bidcos support working. After restarting the addon or the host it suddenly fails to start successfully. Can anyone give me some ideas what I can check or try to get it working back again?

Log of recent startup:

Identifying host system: Raspberry Pi 4 Model B Rev 1.2 (oci), OK
Initializing RTC Clock: onboard, OK
Running sysctl: OK
Checking for Factory Reset: not required
Checking for Backup Restore: not required
Running seedrng: OK
Initializing System: OK
Setup ca-certificates: OK
Starting logging: OK
Init onboard LEDs: init, OK
Starting iptables: OK
Starting network: eth0: link up, fixed, firewall, inet up, 172.30.33.3, OK
Identifying Homematic RF-Hardware: ....HmRF: HMIP-RFUSB/eQ-3 HmIP-RFUSB@usb-0000:01:00.0-1.3, HmIP: HMIP-RFUSB/eQ-3 HmIP-RFUSB@usb-0000:01:00.0-1.3, OK
Updating Homematic RF-Hardware: HMIP-RFUSB: 4.4.18, not necessary, OK
Starting hs485dLoader: disabled
Starting xinetd: OK
Starting eq3configd: OK
Starting lighttpd: OK
Starting ser2net: disabled
Starting ssdpd: OK
Starting ha-proxy: OK
Starting NUT services: disabled
Initializing Third-Party Addons: OK
Starting LGWFirmwareUpdate: not required
Setting LAN Gateway keys: not required
Starting hs485d: disabled
Starting multimacd: ...........ERROR: couldn't setup /dev/mmd_* devices
Starting rfd: ....................ERROR
Starting rfd: ....................ERROR
Starting HMIPServer: .......................................................................................................................................................ERROR
Starting ReGaHss: .OK
Starting CloudMatic: OK
Starting NeoServer: disabled
Starting Third-Party Addons: OK
Starting crond: OK
Setup onboard LEDs: booted, OK
Finished Boot: 3.81.5.20250326 (raspmatic_oci_arm64)