I use the easy installer on my OnePlus 7 Pro. I’m following all the steps correctly, but the moment my phone boots into fastboot mode, the easy-installer hangs. When I manually boot into recovery mode, recovery mode comes from OnePlus. Does anyone have a similar problem with the OP7 Pro?
Do you happen to use Windows 10? In that case it might be necessary to search for optional windows updates while the phone is connected in fastboot mode.
That’s at least one rather common issue listed here: Howto troubleshoot issues with the easy-installer