We have a Delta 2530 series faucet in the onsuite master bath that is causing problems. The water pressure drops way down as the water gets hot. The guest bath has great water pressure in both sinks and the kitchen does as well. My husband checked the meter the other day and the meter turned slow when the kitchen water and the onsuite master bath faucets were run, it ran much faster when the guest bath with the main pressure was running. This has been happening for about a week and we wonder what the problem could be. The shower in this bathroom runs fine with no noticeable water pressure drops. The cold water on the faucet comes out a bit stronger but also has less flow than normal.

It sounds like you have a bad cartridge. In your faucet. I'm not sure what the Warranty is for Delta. Moens is life time warranty. You might call them or research Delta and they might send you a new one under warranty.