To be clear: It connects to the dryer just fine. But once the dryer is running, after some time, it will disconnect. It’s as if the hose adapter just doesn’t hold any grip.
The point where the hose runs outside is clear from any built-up lint.
To be honest, over the years I have had the genuine ones come loose occasionally, even on my own venerable Hotpoint TL 61. I used to wrap a few layers of insulation tape round and round the plastic insert splines before pushing the end in which used to keep it in place (for a while).