Wrong trigger codes in EEG brainvision

I am currently trying to send triggers from PsychoPy via the parallel port.
I have the correct timing of the triggers and all triggers are present in my EEG-file. However, they have the wrong labels. They are always labeled with number between 1 and 15 in Brainvision recorder even though I am sending integers between 1 and 50 as my trigger_value (see the function I am using in PsychoPy below).
Has anyone here experienced something similar? Or have suggestions for how I might solve the issue?