screenshot above shown from "Harry Potter and the Goblet of Fire", a 4K stream without HDR. I went to the same timestamp both on mpv (shown on top) and stremio (shown below). As shown the embedded mpv player within stremio seems to be overexposed in some way.
This also occurs on the rewrite GTK4 branch. Happens regardless of stream I use, I tried HDR streams (which would play in SDR anyway), tried streams without HDR advertised in any way, etc etc, and all exhibited this problem