Check the position of the spring in the top of the trigger. This does two things: the front acts as a trigger return spring, the back, long tail is supposed to be in the slot of the vertical piece (disconnector) that contacts the trigger/action bar in the slide. [Assuming FEG kept the Browning design in this part of the weapon.]
If the long tail isn't in the right place, or if the spring has been pinched by the trigger pivot pin, the disconnector isn't going to properly return to place. If the disconnector isn't exactly where it's supposed to be, that can also cause problems.
How it works: when you pull fire the weapon, the trigger remains back, the slide runs in recoil and returns in battery. The front of the trigger/action bar pushes the disconnector forward. When you release the trigger, the trigger goes forward and the disconnecter is supposed to drop down below the action bar and move to the rear wall of its slot so it can re-engage the action bar.
Note: when you remove the magazine safety, you introduce much overtravel to the trigger. You might try replacing the safety widget without the spring to act as an overtravel stop.
If you're careful, you can reshape the part of the safety that contacts the magazine and reduce the length of the spring and end up with a magazine safety that works, but doesn't negatively affect the trigger. Or at least you can on a Browning.
