We also have the 2901SS, simply love the floorplan and cannot believe that they discontinued it.
Your turbo flush has a check valve at the connection in the sidewall of the camper, I would check that first to make sure it is opening/not stuck. If the check valve is opening properly I would check the connections inside the trailer. If you go under the lower bunk on the side of the trailer all of your water connections are under there. There are a few screws under the cushion holding the 1/8" luan plywood down. I removed all of these screws and left them out, they really have no purpose. Makes access to this area easier. Just inside the wall of the hose connection is an anti siphon valve, this could also be stuck/faulty. If the anti-siphon valve is not the issue the hose from there could be plugged, it that is not the issue from there it is under the trailer. Checking here is more involved since it requires you to remove the underbelly covering for access. Checking here I would call a last resort but the turbo nozzle itself in the side of the tank could be bad. If you have any questions feel free to reply on this thread or PM me. Hope this helps, the turbo flush does a decent job of cleaning the tank if you have the patience to let it run while at the dump station.
If you get it working properly I would suggest that you get a clear elbow connection for your sewer hose, this helps to see (yuck!!) when the tank is clean (the water will be running clear with no chunks).
2011 Rockwood 2901SS Ultra Lite
2014 Chevy Silverado Z71---Hensley Arrow Hitch
my other toy---1969 Camaro 396 SS