[gentoo-user] Re: Root can't write to files owned by others?

[Nikos Chantziaras]

On 10/03/2022 11:55, Dr Rainer Woitok wrote:
Big thanks to all kind people making suggestions.  But up to now nothing
helped.

Are you sure that:

sysctl fs.protected_regular=0

does not help? I can reproduce it here on my system with kernel 5.15.27, 
and setting that sysctl to 0 fixes it immediately.