Open Beta 5 ends the cycle for the 7T series. The official thread includes the rollback builds that will return the device to the 11.0.1.1 estable build. As usual the rollback process will wipe all your data.
https://forums.oneplus.com/threads/...eplus-7t-pro-oxygenos-11-open-beta-5.1451562/
https://forums.oneplus.com/threads/...eplus-7t-pro-oxygenos-11-open-beta-5.1451562/