My magic trackpad, maybe 6 months old, tracks just fine, swipes and scrolls just fine, does multi-finger gestures and two- and three-finger tapping totally normally. Just doesn’t do any normal clicking / tapping. Like almost every Apple product, it’s pretty frustrating to google for. Anyone have any ideas that aren’t turning a setting or device off and on?
https://www.google.com/search?&q=“magic+trackpad”+won’t+click
has lots of results…
Anyway, try removing the Magic Trackpad from the Mac’s Bluetooth System Preferences then power down the Trackpad for a few seconds then try re-pairing.
Good overview: