I'm thinking too lean.
How much fat came out as it fried up in the pan? If it was less than you see with a good quality store bought sausage, that tends to confirm too lean (add more quality fat to the grind). Since you said "patties" in your original post, I presume it was a fresh breakfast sausage. Those can be upwards of 35-40% fat. But you want a quality hard type fat like the fat cap in a pork butt. You can usually find "Fat Back" in the grocery store, but ask if they have any in the butcher section as they often throw it out after trimming from the premium cuts before display and may give it to you. If you buy packaged "fat back" look for some that is not salted. You can use the salted, but you need to adjust the overall salt in your recipe which is hard to do with a pre-packaged spice mix.
I made some breakfast sausage a while back with AC Legg #10 mix. They had pork loins on sale dirt cheap but that a a super lean cut. I was also out of saved pork butt fat caps (yes save them if you are going to trim them off before smoking - that works for sausage), so I came up with the idea of using bacon trimmings in the finished product grind to add fat. Also added that slight hint of a bacon flavor, but it still was not enough overall fat. Those sausage were a little "bouncy" as you called it. Still ate just fine. There was very little fat that came out of those patties when fried which was sort of a surprise (and like I said, and indicator of being too lean a mix).[/QUO