TWRP won't install

Hi all, I’ve a S10 and trying to flash TWRP via Odin or Heimdall.
Both, TWRP and Odin does work and connect to the phone generally, and I managed to install TWRP once. But I faced an issue with storage size. I have 128GB internal storage and it showed only 32GB storage. So I’ve tried TWRP storage size repair function (or so) to fix that issue and it didn’t work. Actually I broke the installation. I’ve fixed that anyways by other means and things appear to be fine (even the storage size issue), after factory reset.
However, since then, I can’t flash TWRP anymore. When I flash, at first things look good, but at the end of the flash process, it still fails.
Same when I try to install /e/OS recovery via Heimdall

Session begun.
Downloading device’s PIT file…
PIT file download successful.
Uploading RECOVERY
RECOVERY upload successful
Ending session…
ERROR: Failed to receive session end confirmation!
Releasing device interface…

has someone an idea how I could fix my S10 so that it accepts TWRP or/ e/OS recovery?
I’ve successfully flashed stock ROM (Android 12) and did factory reset, but it didn’t help with the TWRP or /e/OS recovery issue. So I end up not being able to install either TWRP nor /e/OS.

Thanks in advance any hints or help

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

same issue ?

Doesn’t really feel like the same problem.

I answered with more detail in the thread you linked to…

@piero not sure if it’s the same
@prkfsz I’ll have a look into it.
Thanks both.