Z2 and Collapsible Travel CPAP Hose

I'm having trouble connecting the collapsible travel hose to the QTube on the Z2 machine. Both the collapsible tube and the QTube have hard plastic ends, so even though they fit together it's not a tight fit like you get with a hose that has a soft plastic end, and they just slide apart. I feel like I must be missing something, but I don't know what it is. Any help would be greatly appreciated!

I'm not familiar with the Z2 but this hose connecting adapter should have come with the unit.
https://www.cpap.com/productpage/z1-z2-tube-adapter

For some reason, the Adapter that comes with the Z2 is a bit too small for some hose ends.

I used the elbow shown below to solve for this. I got my elbows with some basic Resmed hoses, and they worked with the Z2.

https://www.cpap.com/productpage/resmed ... p-machines

This is the link from the sponsor, but you can also get them from Amazon. I was actually able to buy the slim Resmed hose with the elbow for about the same price as the adapter elbow alone.