Where are you located (staTe, nearest big city)? How has your weather been - dry,rainy, etc. etc?

Washington State, it's been really hot lately mid 90s. I've attached pics of trunk below. Would you happen to know if that's a canker or normal? Thanks

https://imgur.com/a/qFoIMQC

Too much sun and not enough water. Dogwoods - even the hybrids - are woodland understory trees and become easily stressed in full sun.

With temps in the mid 90's assume you are in eastern WA as western WA has only hit the 90's once this season. But even in our cooler summer weather, established dogwoods in full sun look very stressed. It should recover but will continue to offer this distressed appearance through summers if in full sun

I see no signs of canker but the rock mulch is not doing your tree any favors, either.