Replacing TWRP version on phone (downgrade to 3.3.1.1)

I have a Samsung s9+ 965F which has TWRP 3.4.x on it. From what I read, the reason my /e/ install is failing is because this version of TWRP looks for something involving treble compatible devices. The error I get is: Error 7 Failed to mount ‘/vendor’ (Invalid argument). I did try the fix you find online involving editing a script but it did not work. I think earlier versions of TWRP did not look for this, specifically 3.3.1-1 .

I would like to try that versino fo TWRP the problem is I cannot even replace TWRP . When I try to flash it using adb

adb devices <— I see the phone with this OK
then
adb bootloader reboot ← phone does rreboot OK
then
fastboot flash recovery twrp-3.3.1-1-star2lte.img --no-reboot <— just get an eternal “waiting for any device” message. FAIL

I have no OS at all on the phone. I am wondering if I can just manually transfer the TWRP version onto the phone’s internal drive since I can read/write to it from my Linux Mint box.

I am not sure even I can do do this it will solve my Error 7 issue. I am wondering if there is something else I might try.

Is there any harm in downloading firmware for the same model but a different country? When I go the phone I did not know what contry is hailed from. There’s quite a list here:
https://www.sammobile.com/samsung/galaxy-s9-plus/firmware/#SM-G965F

This is my phone model, but I am wondering if any of them will work or the phone is expecting a certain one? Does anyone know?

Regain your privacy! Adopt /e/ the unGoogled mobile OS and online servicesphone

Fastboot command don’t work on Samsung device use heimdall

Samsung Firmware

It is easier to flash it with windows Odin software
But possible with a GNU/Linux PC with the heimdall-flash command in a terminal.
https://forum.xda-developers.com/wiki/Heimdall
https://forum.xda-developers.com/showthread.php?t=878686

TWRP and /e/

You can try downgrading twrp from the twrp install feature,
download the 3.3.1-0 version .img to the root of the SD card or the internal storage, reboot to twrp, tap on the install bouton, choose select storage, and select the 3.3.1-0.img, swipe to flash the ROM.

Or use the heimdall command with the device in download mode

OK I did do that and I got the same error message … error 7 etc etc etc as I reported before. So to sum up- using the earler specified version of TWRP made no difference.

I can’t understand what the issue is. Does /e/ depend on the original OS being installed?