Got it working now.
The GPG_AGENT_INFO environment variable was not set automatically for some reason.
I had to alter .bashrc to then learn that .bashrc is for some other unknown reason not sourced by fingerterm.
I ended up in automatically let fingerterm ssh in at startup which works (but I don't like it).
Is there any possibility to make fingerterm respect .bashrc (or is there any other place where I can put commands to be executed on fingerterm startup?).
Thanks in advance,

Chris