I’ve got a S9+ that has been running just fine with the “e OS” for a year. I got a new phone and decided to reset the S9+ to erase the data and sell the phone. After the reset, it boots and the “e” bouncing logo just hangs. After a while it will finally reboot to TWRP, but is asking for a decryption password. I have no idea what that password could be… I don’t remember entering one during the setup.
Is there a way to wipe and reinstall the “e OS” to make the phone functional again?
When TWRP asks for a password and you know that there is no password involved you should press “Cancel” to move on. Within TWRP is a Factory reset. This will reset the device to /e/.
Afterward, the phone rebooted and a quick splash showed it was encrypting my data. It then rebooted again, and the “e” logo appeared for a few minutes, then the phone rebooted again into TWRP.
So you really want to flash a new ROM in the same version as your previous one
If you did the OTA Update in February it is much more likely that you received the Android version Upgrade, as described here. OS OTA Upgrade of S9 / S9+.
If you knew this were the case then today you should flash an Android 10, Q ROM, which you would find as a dev build. For dev vs stable please read this Different Build Types.
