Passing Specular BSDF through Shader->RGB when SSR is enabled causes shading other than ambient world lighting to be removed, not just the SSR reflections. The same happens with Glossy, Principled etc.

2.93:

2.92:

After bisecting, this was found to be caused by https://developer.blender.org/rB7f7e6830991 but it's a large commit so I didn't dig in and find exactly what was responsible.

(If I've already found the commit/cause should it still be opened as "Needs Triage"? Would marking it as "Confirmed" be presumptuous?)