That is weird! My first thought would be changeover valve, but if you say that's not blocked...
The u bend at the bottom rear that makes the suction channel to the wand, is it there, and does it meet with a rubber seal underneath the machine?
Best way to check the motor pitch is to turn it on upright, when there should be suction pouring out of the hose, then take the cyclone off. You should hear a blatant massive difference!
Failing that, it'd troubleshooting time.
The suction goes from the motor to the right hand higher hole on the chassis (with the bin off, check that with your hand)
From there it goes through the cyclone, through the left hand lower hole then down to the lh (as you look at it) changeover valve. Remove the blockage channel at the lower lh side and check for suction. Should be there when reclined and upright.
Next, take the wand and hose off. Hose comes off by removing the wand, pulling the tab at the top of the bottom hose bit out and pulling up. Hose should come off. Is there suction coming out of where the hose went when the machine is upright?