foreground selection crashes gmic 3.2.6 as well as 3.3.0

Using gmic_qt or the Gimp gmic plugin - on Linux Gentoo -
I select foreground and background points and enter ‘space’.
This seems to work, but selecting further points and entering ‘space’ again, makes my CPUs busy
for some time but then the interaction window disappears and I cannot terminte GMIC normally.
All buttons but the Cancel button are greyed out, and clicking on the Cancel button doesn’t
do anything. I have to kill / x-kill GMIC.
What I am doing wrong.
I have 64GB RAM and GMIC used to work just fine earlier.

Many thanks for a hint,

Hello Helmut,
It works fine for me with a test image.
Could you record a video of your process so we can try to understand what happens?