Communication only one directional

[n0valis]

I have connected my Raspberry Pi5 via signal-cli and my landline. I did thsi two days ago with my WSL and it worked perfectly fine but I wanted to have it on my Raspi now. Installed signal-cli-0.13.23 and put libsignal_jni.so into the lib dir and added
DEFAULT_JVM_OPTS='"--enable-native-access=ALL-UNNAMED" "-Djava.library.path=/home/smaug/.clawdbot/tools/signal-cli-0.13.23/lib"'
to signal-cli
I copied the ~/local/share/signal-cli folder over to te Pi and I got to the point where I could send messages to my phone.
But not vice versa. Sending messages back to the Pi resultedin one checkmark only status to all ma send messages.
So I started debugging and did everything from ~/local/share/signal-cli folder and re-registering to deleteing the contavt from my phone, used several commands like signal-cli listDevices, updateProfile, receive -t 30, trust -v "61726..."
Nothing helped. I am still stuck with the one directional coms.

Testing:
signal-cli -a +12345 send -m "Loopback Test" +12345
1769781806780
signal-cli -a +12345 receive
nothing...

What the heck is going on here?