So I wanted to root my OnePlus 6 after updating to android 10 (OnePlus6Oxygen_22_OTA_041_all_1911142043_dde113e5 3cd0f9.zip)
I tried booting into twrp via fastboot using
fastboot flash boot twrp.img
(twrp-3.3.1-x_blu_spark_v9.101_op6.img, my bootloader is unlocked).
I then tried rebooting directly into twrp, but now it's just stuck on the "Bootloader is unlocked" screen.
I can still boot into fastboot, but I can't boot into recovery or reboot normally since it just gets stuck on the bootloader unlocked screen.
Edit1: Changing my boot slot from b to a gives me access to the stock recovery. not sure where to go from here though.
Edit2: Fortunately, ManikandanGuru over at xda had uploaded the stock boot.img, which works perfectly.