ANy time you shut off the water, you can dislodge crud when you turn it back on. My guess is that you have some caught in the supply line or cartridge guts on the hot side. It could be at the shutoff, the hose, or internal. Take the supply hose off the shutoff, use a bucket, and see what kind of flow you get out of the shutoff directly. This will help start to isolate where the problem is.