Yeah my Bad that was for The 855. And there IT says in The Post that IT only works Up to 21c but Not sure If thats still a Thing.
So have you tried flashing a Modem? And does IT Work now?
Check your inbox I will send you some information regarding your problem. I will attach an IMEI free backup of the device I had so you can flash the partitions. Remember my backup also contains boot.img and other partitions so ...