Have you tried the John Guest fitting?
Yep and I find they come apart hence keeping it simple.
Have you thrown away the little red clips that come attached?
When I first got mine I took them all off & chucked them. Assumed they were for transport or something.
Turns out their not.
They stop the hose pulling out accidentally.
On my next purchase from Gardiners I asked for 9 new red clips. They chucked 'em in for nothing.
Hose hasn't popped out since.