Sometimes American carriers and unlocked phones don’t mix well—the authentication systems don’t work together correctly. That appears to have happened with some of the first batch of new OnePlus phones that came into users’ hands, the 8 and 8 Pro. Though Verizon is selling a branded version of the OnePlus 8, owners of the unlocked versions were having trouble activating Verizon SIMs.
According to Android Police, that problem has been resolved. The issue seemed to be around IMEI number certification, part of the network’s system of tools to authenticate devices and users. It’s possible that some users might still need to contact Verizon support to enable the non-CDMA devices onto the LTE network, but for the most part, slipping in a Verizon SIM to the OnePlus 8 or 8 Pro will now work as it should.
Note that only the Verizon version of the OnePlus 8 is guaranteed to work with Verizon’s 5G bands. Verizon doesn’t sell the OnePlus 8 Pro, but the unlocked versions of both phones are compatible with most of Verizon’s conventional wireless bands.
Source: Android Police