The battery is good. Any ideas?
You say the battery is good...how do you know?
The solenoid tripped, but it wouldn't turn the starter?
Batteries will show 12+ volts static, but not have any cranking amps to turn stuff over.
I would first get the battery load tested, an also remove and clean all four battery connections (2 hot side and 2 ground side).
Our member here 85Hokie would say all battery connections should be "bright and tight."
Betting you changed a good starter because of a bad battery or connections. Trust me, you won't be the first to do so.
Just guessing...but it's where I would start. I'd bet 50 guys had same issue here on OTT in 2018....
Good luck... And welcome to OTT! Great group we have here!