Just a reminder for people who only read the oneplus 9 forum and not oneplus 9 pro one:
forum.xda-developers.com
I tested it and flashed it on my oneplus 9 LE2110 and it works.
Again, as i always have to write to people.
Be careful, only do something you can undo.
Before you "Flash Current TWRP" do a full BACKUP!

[RECOVERY] [11] [OFFICIAL] TeamWin Recovery Project
Introduction: Team Win Recovery Project or TWRP for short, is a custom recovery built with ease of use and customization in mind. We started from the ground up by taking AOSP recovery and loading it with the standard recovery options, then added...

I tested it and flashed it on my oneplus 9 LE2110 and it works.
Again, as i always have to write to people.
Be careful, only do something you can undo.
Before you "Flash Current TWRP" do a full BACKUP!