multiport makes clinking sound

multi-port is making clicking sound when I move it from filter to waste to rinse and back. Last year it was silent, still works though.
maybe an issue in the future.

Any advise

Thanks

You probably have a small problem with the spring under the handle. It's a bit of a pain to take apart and reassemble the top plate/ handle/ spring - I'd wait until it was necessary ;) and then we'll tell you what to do to fix it.