u/Callexpa

Hey everyone.
I have two different bagpipes from two different builder, and both use the same type of rubber head as a oneway seal on the blowpipe.
Yet on both pipe, these seals get leaky, resulting in quite a lot of air coming out of the blowpipe when I apply preasure on the filled bag, and also making a lot of wet noises as well.

Am I handeling them wrong, do I need to replace them (everytime that happens?) and if so, where or how do I get replacements, or is there a common way to fix this up?

Thanks