Verizon requires any OEM that sells unlocked devices with support for its LTE 4G network to apply for certification. When OnePlus began selling the 8 and 8 Pro from its online store in the US on April 29 - neither of these phones were officially supported on Verizon's network. OnePlus initially issued a statement prior to the 8 and 8 Pro's launch that it would not be compatible with Verizon until possibly June. In a turn of events, effective immediately, US unlocked variants of the OnePlus 8 and 8 Pro can be activated on Verizon's LTE network. The news was brought by Verizon Corporate PR...
Source: https://www.gsmarena.com/unlocked_oneplus_8_and_8_pro_now_officially_supported_by_verizon_in_the_us-news-43022.php