i saw there some questions about TWRP and android 10. So far you cant boot TWRP on android 10. It doesnt matter Q BETA DP4, 5 or OB1.
Mauronofrio is already informed about that. There is some work needed to fix that.
But there is a way to flash TWRP with Magisk! I already posted that a few times in TWRP thread and opened this thread now. So it's easier to find it.
You will need to have magisk on your phone to do this!
UPDATING FROM ANDROID 9:
1. Install Android 10 trough local Updater AND DONT REBOOT HERE
2. Flash TWRP trough Magisk
3. Install magisk to inaktiv Slot (after OTA)
4. REBOOT NOW
With OB1 it also works the usual way:
1. Boot into TWRP and Flash OB1
2. Flash TWRP Installer.zip
3 Reboot directly into recovery
4. Flash Magisk and reboot system
COMING WITH ANDROID 10 NON ROOT:
COMING WITH ANDROID 10 AND ROOT:
1. Flash TWRP with magisk
2. Install magisk and reboot
Thanks @tidschi for correcting me (patching boot.img) and screenshot