FIXED: Check edit at the bottom.
Okay, I decided to check MPV configuration file. Cut all the lines, clicked save, started the video and everything worked. Went back, clicked paste, same issue came back. So something changed in the update that's breaking SVP from working with MPV using these settings below, I'm going to try to narrow it down to what's causing the issue:
vo=gpu
profile=gpu-hq
fbo-format=rgba16hf
gpu-api=vulkan
gpu-context=winvk
hwdec=nvdec
spirv-compiler=shaderc
priority=high
scale=ewa_lanczossharp
cscale=ewa_lanczossharp
dscale=ewa_lanczossharp
dither-depth=auto
correct-downscaling=yes
sigmoid-upscaling=yes
deband=yes
deband-iterations=4
deband-threshold=50
deband-range=16
deband-grain=0
vd-lavc-dr=yes
vd-lavc-threads=16
sub-ass-shaper=complex
sub-font-size=35
sub-scale-by-window=yes
sub-pos=100
sub-align-x=center
sub-align-y=bottom
sub-margin-y=3
hdr-compute-peak=yes
glsl-shader="C:\Users\musta\AppData\Roaming\mpv\Shaders\KrigBilateral.glsl"
profile-desc=cond:get('height', 0) < 1440
glsl-shader="C:\Users\musta\AppData\Roaming\mpv\Shaders\FSRCNNX_x2_8-0-4-1.glsl"
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EDIT:
Changed hwdec=nvdec to hwdec=nvdec-copy and now it's working. I always used hwdec=nvdec before without issue though, weird.