No cell service, but imei shows up

Hey yall, I recently bought 4 iphone 12 minis, 2 I figured unrestorable, but 2 both have the same issue and I dont know what to do about it. Both devices have failed the "Cellular RF" test. Well one of them specifically says "Cellular RF Front End Scan." I dialed *#06# on both devices and the imei did show up. Im still not sure if this could be a board issue or a issue eith an antena. I put the sim in a known working US version iphone 13 and it worked. One device is the Europe version and the other is a Chinese version but with a US housing. SIM is from Megaphon Russia.