Indeed, I do not know the logic of Gura punch blocking K-Room, just like I don't know the logic behind Gura punch blocking Akainu's magma attacks and yet, both are manga facts.
On the other hand, we have Law fans, who make shit up that doesn't exist, to justify some headcanon.
Can you tell the difference?
Law isn't the only user of Shockwaves, bruh... There are always indicators of it. You are simply missing it where you want it to be.
You didn't give valid explanation, you have a headcanon and you are trying to make up things that do not exist...
You know what does exist tho? SFX Gaching!! which is used when two hard surfaces collide aka K-Room is treated as a tangible object.