“Hop Creep” is a thing. Using T-90 pellets in the dry hop can cause refermentation due to the plant material interacting with the yeast. This can further dry your beer out, or cause excessive diacetyl production.
I like to use cryo-hops to avoid this and keep my T-90’s in the kettle. You can also just give your yeast a few extra days to clean up the diacetyl. Some yeast strains that tend to flock really well may have a problem here. Just make sure you transfer the beer off the hops by day 10 to avoid vegetal off flavors. Brewers have seen a huge increase in “Hop Creep” due to turn over times in the cellar decreasing significantly in recent years! Cheers!