While the OnePlus 12 works fine on Verizon, the same unfortunately can't be said about its more affordable sibling, the OnePlus 12R. According to some user reports, the phone simply doesn't work on Verizon, even though it definitely should. It's the first time that an R series device launches in the US, and it seems like the launch wasn't prepared properly from OnePlus' side. One user on XDA forums explains the issue quite eloquently, describing that out of multiple 12Rs he purchased, all are "Invalid IMEI" on Verizon. OnePlus customer support has apparently been stringing him along...
Source: https://www.gsmarena.com/oneplus_12r_isnt_working_on_verizon_yet_although_it_should_be-news-61620.php