TWRP 3.3.0 cannot decrypt data partition (of Android 9)

Question

I just updated to TWRP 3.3.0 from older PitchBlackTWRP but now TWRP does not ask for the password any more. Tried manually decrypting and manually wiping from TWRP terminal. Did not help.

recovery --wipe_data
twrp decrypt <your password>

How does Android encryption work? Does TWRP need except the password some device key?

Booting the system still works fine, so still everything is available what's needed for decryption.

Yes, I saw TWRP OnePlus 5T not asking for encryption password , but the solution did not help. And I am not allowed to comment.

Should I reinstall PitchBlack-TWRP?

ps. I don't need the data, did a backup before.

Answer 1

Well, sorry for bothering. The solution was simple: Don't use the wipe function of TWRP but the Format Data button in the wipe menu.

I was able to factory reset and install a different custom rom.

BTW: Don't use TWRP for Android >= 9 (Pie). As of Version 3.3.0 TWRP lacks the vendor partition feature. Pitchblack seems to be the standard now.

Edit: I think the problem is: Android 9 introduced the quota feature of the ext4 filesystem. TWRP doesn't know about it yet.