PTFE tube doesn't stay connected to the back of the CFS unit

I have ongoing issues where the PTFE tube intermittently pops out from the CFS back connection. I’ve swapped out the PTFE tube and/or trimmed it back, only to have it recur.

Is there an easy replacement for the PTFE connector, and if so, anyone who can direct me to what connector to order (Amazon would be easiest). This is frustrating to say the least. I can’t find any specific technical videos for this and it would be terrible to have to replace the entire feeding unit.

Thank you!

Where in the world are you ?

I live in the USA.