Issues with file save path

[lpaderiAltravia]

Hi,

I am running PopOS 21.04, and I have installed the latest version from flatpak (user).
PDFtricks does not seem to understand where I want to save my output file, and always puts my documents in /run/user/1000/doc/I_guess_some_kind_of_uuid.

The outputs are correct, but the location is wrong.
This is what is logged in the console, although I am not sure if it is relevant

GLib-CRITICAL **: 14:58:02.450: g_variant_new_string: assertion 'string != NULL' failed 

PopOS 21.04
Intel 11th gen i7-1165G7