When breaking blocks, the cracks that appear when the block is in the process of breaking glow bright white.

AMD Radeon RX 7600 XT
Windows 11
Minecraft version 1.21.1
Iris ver 1.7.3
Bliss v2.0.4

Other mods installed:
-sodium 0.5.11
-lithium 0.13.1
-tectonic 2.4.1a
-fabric-api 0.105.0

It's definitely a problem with the shaders because when I disable them the problem disappears.

this is just a problem that came around when iris changed the behavior of the lightmap coordinates in the shader program responsible for the cracking effect.

there is no fix; you will just have to use a newer bliss version where i redid how that effect was handled. download the in-development version from the main github area (read the description there)