Should I be concerned?

[Sted-E Ed-E]

Some powder is very green colored that is not an issue.
If you have a chrony you could shoot some through it to test or just pattern both rounds and see what you get.

I would not worry about height of the "brass"

Good to know, I don’t have a chronograph, but I’ll see how they shoot this weekend.

 

[Forgalspop]

Stick your finger in the chamber and feel for a ridge alongside the top left had side of the chamber. I’m willing to bet you’ll find one. I had one on my 2012ish vintage 870. Took the shotgun apart, Dremeled the burr off, polished the crap out of it, and never had the problem again. First three shells I shot out of the shotgun before fixing this resulted in me having to mortar strike it to extract the shells.

Will follow your advice. Thanks!