You bring up a good clue. One of my cars that I take out often during the fair weather months to cruises has had issues when I go to start it, it just clicks. Sometimes the starter would turn for a split second then I’d get the clicking.
I’d grab my battery terminal cleaner and give it a brief clean up, reconnect the battery cable, and then it would turn over and start fine.
I keep a battery ground cable disconnected on my vintage cars when they are parked in the garage. There’s no corrosion on the battery studs or clamps so I have never figured out why this happens. And since a quick scuff with the terminal/clamp cleaner resolved the problem, I just consider it a minor inconvenience.
This year just for the heck of it I put some grease on the battery stud after the first time the clicking happened, and haven’t been having the problem since. I don’t recall now what I used, white grease maybe.
So even if there is no corrosion visible, try cleaning the battery studs and clamp and see if that helps.