@Helium3 Yes the Ender 6 comes with one, it doesn't help with this problem though.

@Helium3 good suggestion but I've already done that and replaced the couplings on both ends with better after market versions, it still happens.
I found a compression fitting on Thingiverse that may help but from what I've seen online the bowden tube system itself is flawed.

My problem is this, the coupling that’s supposed to hold the bowden tube in place on the cold side over time fails. As the printer deposits and then retracts the filament the friction in the tube causes the coupler to dig into the tube and eventually the coupling can’t hold onto the tube any longer and it slips out. I asked Creality support what to do about this and they said to replace the coupling. I’ve replaced both the coupling and bowden tube, but the same thing continues to happen. At this rate I’ll probably be replacing couplings every 100 print hours and tubes every 300-500 hours. This seems like a waste, are there any better options for securing this connection?

Just wanted to know if you've had any luck switching tubes, I'm having the same problem.