[TL-MR6400] Unable to connecto to cellular network

I've just flashed the latest stable version of OpenWRT into my TP-Link TL-MR6400 4G router and as far as I could tinker, it works very nice.

However, I'm unable to get my cellular network working. I checked that all required packages are installed, and all settings were set up correctly but OpenWRT throws me errors. Checking system log I see:

Tue Nov 14 14:06:37 2023 daemon.notice netifd: cdc (3129): Waiting for SIM initialization
Tue Nov 14 14:06:38 2023 daemon.notice netifd: cdc (3129): Failed to parse message data
Tue Nov 14 14:06:38 2023 daemon.notice netifd: cdc (3129): PIN verify count value is 1 this is below the limit of 3
Tue Nov 14 14:06:38 2023 daemon.notice netifd: cdc (3150): Stopping network cdc
Tue Nov 14 14:06:38 2023 daemon.notice netifd: cdc (3150): Command failed: ubus call network.interface notify_proto { "action": 0, "link-up": false, "keep": false, "interface": "cdc" } (Permission denied)
Tue Nov 14 14:06:38 2023 daemon.notice netifd: Interface 'cdc' is now down

And, on Network > Interfaces > qmi-cdc device:

Error: Unknown error (PIN_TRIES_BELOW_LIMIT)

After hours searching on internet, I couldn't find any information about this error. The PIN code from SIM is correct, and carrier configuration is also correct. I don't know what to do. Any ideas?

Not sure where it comes from...
Check the SIM in a phone, disable PIN if enabled.
Uninstall whatever you installed to support the modem.
Follow instructions from the wiki: https://openwrt.org/docs/guide-user/network/wan/wwan/ltedongle