Yeah it does happen. What probes are you using to profile printers? How they are appearing on ISE once profiled. ISE profiing
From experience, I have noticed that some devices will get profiled generically. We use IOS Device Sensor/Radius as well as DHCP helper to cover all the cases. Still sometimes I will see a Cisco IP phone get generically profiled as "Cisco-Device". I messed with all the device sensor filters as well as looked at what the Identity info looks like(is it using DHCP or Radius to profile). On some of these one-offs I had to put a mac-address contains line in the profiler. That is the quick and dirty fix..