Is it a mod compatibility issue?

Yes

If it's a mod compatibility issue, please provide the link(s) to the incompatible mod(s)

Sodium

Minecraft version

1.20.1

Describe the issue

Immersive Portals crashes when installed in the same instance as Sodium 0.5.8

I second this request.

Tested out shader compilation is broken if we force immersive portal 3.3.9 to load with sodium 0.5.8

Shader compilation log for sodium:blocks/block_layer_opaque.fsh:
ERROR: 0:73: 'out_FragColor' : undeclared identifier 
ERROR: 0:73: 'scalar swizzle' : not supported for this version or the enabled extensions 
ERROR: 0:73: 'a' : vector swizzle selection out of range 
ERROR: 0:73: '' : compilation terminated 
ERROR: 4 compilation errors.  No code generated.

Seconding this, I'm trying to make a decently sized modpack and this is the only incompatibility that I'm having an issue with right now.