The scavenge side of the system is not working.
Your pump is pumping oil into the motor, but its not getting back out.
Under your sump cover is a small pipe with a check ball in the end. Thats the suction pick up tube.
Check and make sure the end of the pipe is clear. Poke at the ball a little to make sure it moves freely.
If that all looks ok, I would remove the return line from the back of the engine and kick the bike over (dont start it!) and see if oil is trying to return.
If oil is trying to return, you might have a blocked/collapsed oil line leading up to the tank.
Lee