The safety cam and the safety link both will cause that.
Engage the safety. Lay the gun on its left side and give it a few good bumps. Then disengage the safety, stand it barrel up and give it a few more bumps. When you get it to go off then tale it out of the stock.
Youll see the safety cam on the left side of the trigger. Make sure the clip is on the pin. Make sure the spring on the anti bear trap linkage isn't broken. The only other possibility is the link under the safety button itself, broken trigger, etc.
I've had the same problem many times. A couple of mine I removed the safety cam because the linkage was broken. It's all fairly easy to repair or bypass but you need to bump it around until you can get the gun to fire. Otherwise you have a cocked gun on the bench out of the stock fiddling with the trigger.
You can manually set it off with a wire by pushing down the sear. Take out the second stage adjustment screw and push a fine punch in there to fire the gun. If jiggling does not do it then go at it that way. But don't take it out of the stock until you release the spring.