Archer MR200 v6 cannot connect to Play network in Poland - fixed

Bought a brand new Archer MR200 and a SIM card from Play.

Tested the SIM card in a phone to make sure it works.

The modem kept on disconnecting with the following errors in the log and would show IP and DNS as 0.0.0.0:

USER: Start connecting to the network! 
USER: GetCurrProf result is:ipver:2 staticApn:0 authType:2 pkgName:PLAY profname:PLAY apn:internet usr: psw: 
USER: Get ISP's profile now. 
ERROR: Verbose Call end reason = 2001 , type = 3. 
ERROR: Call end reason = 3. 
ERROR: OxOOOOOOOE QMI_ERR_CALL_FAILED
ERROR: Verbose Call end reason = 2001 , type = 3. 
ERROR: Call end reason = 3. 

USER: Dual Stack meet Call Fail, reattach 
ERROR: Verbose Call end reason = 33, type = 6. 

Did the following steps to make it work:

1. Upgraded firmware to Archer MR200(EU)_V6_230311 (https://www.tp-link.com/pl/support/download/archer-mr200/#Firmware)

2. Configured 4G only in the network options

3. Manually added a new network profile - copied everything, but changed PDP to IPv4 instead of IPv6 and IPv4

The modem would also work fine when setting to 3G only, but then the speeds were only around 3-4 Mbit/s. After applying the 4G settings above & putting it outside the window, speedtest.net measured about 20-30 Mbit/s and the connection was fairly stable.