My tool adapters for the Dirt Devil stick vacuum cleaner worked fine when inserted into the power unit, but got stuck in the floor brush extension tube:

The adapter rotated freely inside the socket, so its diameter was correct and it wasn’t jammed, but pushing the latch button (at the depression on the right) didn’t release the adapter.
Popping the latch out of the tube let the adapter slide easily out of the socket and exposed the innards:

The two bosses inside the latch originally captured a nice conical spring:

The tab on the left side of the latch button engages a slot in the OEM brush head and the recessed ring around my adapters:

It turns out the molded tab was slightly too long, so pushing the latch button all the way down didn’t retract the tab out of the bore, so it remained engaged in the adapter’s ring.
The conical spring also didn’t seem to collapse completely flat, so the bosses inside the latch button couldn’t quite bottom out, leaving the tab protruding even further inside the bore. It also required an inordinate amount of force to push the latch all the way down.
While fiddling with all this, I noticed that the OEM floor brush would sometimes hang up on the tab, so the operation wasn’t all that smooth even with the original equipment.
So I trimmed maybe half a millimeter off the tab, just enough to release the adapter with the button fully pressed and without the conical spring, then replaced the conical spring with a tiny spring (from the Big Box o’ Random Springs) trimmed to allow the full range of travel. This not only released the adapter, it also let the OEM floor brush pop out more easily.
A zero-dollar repair, although with considerable annoyance.