You need to take a photo from further back. I'm not understanding what that piece is between the counter and the range? Is that a seam there?

When they initailly installed the counter top they removed a riser that was under the old countertop and this made the new countertop too low. They installed a piece of trim to fill the gap between the counter and stove.

Were I the warranty agent on this call, I'd look for topical evidence of heat damage like a look and/or feel of finish changes on the deck. I'd also look to see whether or not the top was properly supported.

I could not help but noticed the horrific caulk job between the deck and splash. That's a warranty claim in itself.

I was hoping you would chime in

@Joseph Corlett, LLC would that little hole shown in the third picture be indicative of anything in particular

Is the weight of the range pressing down unevenly on that riser and then on the counter? Science and gravity would say that that could account for it cracking the corner.

is that a really tall range or a short counter?

Short counters 🥴

"@Joseph Corlett, LLC would that little hole shown in the third picture be indicative of anything in particular?"

Unlikely.

I am a fabricator. If there is no evidence of heat damage the likely cause is a flaw in the material. It doesn't happen often and usually if there is one the piece will break during fabrication but I have had a few failures after install. In one instance a corner broke off on a small counter at a bank where there was no likelyhood of heat damage. The fabricator should replace the part.