Triggers not sent correctly using Builder and Brainvision

PsychoPy version (1.84.2)
I have built an experiment using builder where a trigger is sent every 2.5 seconds. This experiment ran perfectly in one of our lab’s set ups. However, when I test it in our usual set up some triggers are not being sent. This changes every time I test it, if I restart the computer the triggers that are not sent are different, there is no systematic error. There is no error line either. Triggers are sent via a parallel port connected to the eeg acquisition computer. We have tried changing the cable in case it was broken, and it still doesn’t work.

However, this parallel port is shared with two acquisition computers: EEG and NIRS. My doubt is, has anybody had the same problem before? Or, has anybody used the same parallel port cable with two different acquisition systems?