Why is my DC17 Dyson hose sucking itself shut?

I’m getting ready to crack open my DC17 again as I can’t seem to fix it, but thought I’d see if there were any other ideas here. I have a Dyson DC17 upright. It has started overworking itself it seems. It will suck the hose near-closed in the upright position and overheat (has powered off once).

The hose line is clear of clogs. The brush is spinning. I thoroughly cleaned the washable filter and let it dry for a week just to be safe. The u-line is clear of clogs. Took apart the cyclone canister and cleaned out the individual root cyclones. Problem must be in the machine and not the canister?