I get a mild, "clunk," sound (air) while the water is running, and this
happens in only one faucet in the whole house:

While the cold water is running for a few seconds, there will be one
single mild "clunk," in the line (while water is running). It won't
clunk again while the water is running. However, if, while the water is
running, I move the lever over to the, "hot," position, then it will
clunk again (just once). Now, ifI leave that hot water running, there
will be no more, "clunks," unless I move the lever back over to the,
"cold," position, then I'll get another, "clunk." This will happen about
4 or 5 times. Eventually, it won't clunk anymore, regardless of how many
times I switch the faucet back and forth between hot and cold.

If I turn the faucet off and wait an hour or so, I can repeate the whole
process.

Any thoughts on this please? Thank you.