The fact that the release sleeve appears to be stuck in the "open" position in the first picture gives me little faith that whatever springing mechanism keeps it in the "locked" position actually works well in service. Take a look at a google image search of any of these kind of connectors, from any brand :
They aren't jammed in the open position when not connected to anything. You describe the sleeve as "loose" - it shouldn't be. It should spring to the closed position or if it's one of the few types that are either open or closed, it shouldn't be "loose"
When in service it stays in place by those white fingers (3 of probably) inside the hose end gripping onto the ring above the rubber seal of the tap end. Crude sketch time:
The yellow arrow things in my sketch are those white plastic fingers. They hook onto the collar of the tap end (light grey) and stay in place because that outer sleeve stops them from springing outwards - in effect the sleeve holds them inwards. When you pull on the sleeve, the bit of plastic that pushes the fingers inwards moves down, and away and another part springs the fingers open so they no longer grip the collar. You can see this in action if you look at the movement of the white fingers while you move the locking sleeve between open and closed. The rubber ring(black in my sketch) seals the water (blue) in
Now imagine if the molding was poor quality and the collar/finger/both ended up sloped instead of a good sharp 90 degrees. This is common with low quality connectors:
It's going to be a lot easier for the water pressure (which is basically always trying to pull the joint apart in the same way you would by yanking on the hose) to separate; those angled surfaces will actively and more easily slide over each other forcing the white plastic fingers open (especially if the spring on the sleeve that releases them is weak, and cannot resist the fingers being forced outwards)
It doesn't take much imprecision to make slippy, bendy materials like plastic give way, and there's a lot of pressure in a hose, relative to these puny plastic fingers. Any additional effort you supply such as bending the hose back and forth as you water, or it rotating as it is connected, only helps further separate them if they aren't well made
Short version: I strongly suspect your connector set is junk and should be swapped out