I am currently collaborating with 2 other developers and between us (possibly even on the same machine between different changes) the “m_IndirectSpecularColor” property of the serialized scene file changes all the time.
Also a Google search of just “m_IndirectSpecularColor” brings up tons of git change lists where exactly this behaviour can be seen.
Is there any way to avoid this?
Did you ever find a solution? I downgraded from a higher HDRP and it seems to be happening in 7.3.1, but I don’t recall it happening when I was using like 8.x
It happens to me between Linux and Windows, and I thought it was because of OpenGL vs DirectX float precision or something, but other devs seem to have it without changing OS. Maybe the graphics pipeline itself changed number precision or format?
Not a solution but at least I found a repro case. Unity Issue Tracker - m_IndirectSpecularColor changes when another URP scene is reserialized
Anyone found a solution recently? This is a major pain with merging. 
Fixed
Try turning off the Recalculate Environment setting.
Window > Rendering > Lighting window > Scene > Workflow Settings > Recalculate Environment