Marui, WE or Bell glock
stock trigger safety should looks like this.
The "spikey" thing on top is supposed to be elastic and straight. When the trigger safety being pushed in, the "spike" get bent. When finger moved away from trigger, the spike should push the trigger safety out. There is no metal springs or coils for the
stock trigger safety. I don't think your stretched pen spring will help.
If that piece get bent for too long and not coming back straight, or not elastic enough (surprisingly common on WE Glocks), or get snapped, the trigger safety will not function.
I replaced the trigger safety parts of my WE Glocks to TM parts (I think it is $0.8 on WGC). No more problem. I probably should buy another $0.8 TM trigger safety for my Bell Glock which has a functional but weak trigger safety.
The replacing of the trigger safety is very easy to do. You just push the small pin holding the trigger safety (NOT the big pin holding the trigger) out, take the old trigger safety out, put the new one in, and put the pin back. The trigger do not need to be taken out of the frame for the replacing.