Window question

[Tailwind]

Just lately, my passenger side window makes a fairly audible "click" when it reaches full open or full closed. If I stop it when it is almost opened or closed, then continue, it will do it intermittently. Doesn't matter if the door is open or closed.
Otherwise, it works fine, not a show stopper, but there's certainly something going on. Any insight from knowledgeable members?

Thanks!