We have an old Electrolux canister model vacuum cleaner with a working power nozzle. I attached the power nozzle to the canister and used it; it was fine. But now I can't detach the hose from the canister. I realize that I'm supposed to push in the two metal tags and turn the hose, but the hose won't turn. What to do, please?

Vacuums - Electrolux - Central Vacuum