Strawberry jam is notoriously difficult to get it to set. Sometimes a batch will work and you'll do it again, do everything the same, and it won't.
Reboiling with extra pectin (jamsetta we call it) might do the job. Also add some lemon juice as well to be sure.
I've never had a problem with overripe strawberries particularly, as long as you add enough pectin.
Sorry it didn't work for you, but tip it in your pan and try again.
Oh and on the pan, what are you using? For jam it needs to be a wide shallow ish pan rather than a deep one, as the heat needs to evenly distributed throughout.