Media players like VLC or MPC-HC are recommended for handling high-bitrate files on PC.
Furthermore, the original camera negatives for SSIS-903 were reportedly shot on 6K sensors, downsampled to 4K. This means the 4K release contains more detail than the original 1080p release, which was a downscale of the same 6K footage. You are seeing the maximum fidelity the source material can provide. ssis903 4k