When mixin.perf.faster_texture_stitching is true, textures like melon stems, copper, and dandelions will be corrupt. It's unknown which mod is making ModernFix do this,

Log: https://mclo.gs/GrFb2Qa

Try installing Iris, even if you do not use shaders. There is a known bug in Sodium on older versions that causes this issue which Iris includes a workaround for.