Lines.cfg overlay filter causes my displays to have washed out blacks

lines.cfg is by far my favourite overlay, I only discovered it recently and it has transformed retro games for me. Most of the time it works fine on the XBOX Series X, however sometimes it will cause my display to wash itself out, basically the blacks will look too bright. This problems happens regardless of whether I am playing on my TV or my monitor. Weirdly enough, the problem will suddenly go away but then return sometime later.

I have tried resetting the system, going back and forth between retail and dev mode, trying to change the resolution between 4k and 1080p, messing with the colour output etc. but it is always the same result. As I said before, the problem will just suddenly fix itself eventually.

I am also using it on my Playstation Classic on both displays and it gives me no problems whatsoever. I have had to set Overlay Scale to 1.50 to make it look the same since the PSC only outputs in 720p.

Is there any solution to my problem?

Edit: Managed to fix the problem (for now at least). I set the fullscreen resolution to 1920x1080, now the overlay no longer causes the visuals to look washed out.