If I am remembering correct from my mind archive, some members reported to not use red window and need of black tape it when using it with modern films. I am remembering that I was using Kiev 88 magazine without problem even without red window and velvia to isopan.
You can even touch the film backing with Kiev magazines.

I did not use above camera with film but my first observation was the film advancing knob is turning to infinity without care of advancing per 6 centimeters.

Now can I use red window without problem with Portra to Tri X ?

I need to add there is a sliding metal window to close the red window also.

Thank you,
Umut