Melted airlock - Help!?

[An Ankoù]

Not watched it but put "rubber can cause plastic parts to melt" in YouTube.

Interesting video even if the voice is grating. Sounds like the guy in "The Good Doctor".

 

[markeemaark]

Not watched it but put "rubber can cause plastic parts to melt" in YouTube.

Just watched the suggested video and yes, this is a very similar reaction. Thanks Clint.

 

[Chippy_Tea]

I have never used white bungs mine are all the red ones below maybe its those that are causing the problem.