I've had this issue for the past year or so where the trunk latch won't engage after the trunk release button on the fob or the dash is pushed. When I do press the trunk release button, the latch motor (solenoid possibly?) makes a buzzing/screeching sound. I've fixed it a few times before, but have never actually figured out what it was that fixed it. Currently I've pulled the fuse to keep trunk light off so I don't keep draining the battery. Any ideas?
If the trunk releases manually, but does not open with the fob or interior button, the problem is likely a failed trunk solenoid. Especially since you said it makes a strange sound when you attempt to open it. That implies that the solenoid is getting proper power and ground - it just isn’t working.
I suggest you have a professional inspect your vehicle’s trunk in person to determine if my diagnosis is correct. YourMechanic is an excellent option since we make house calls.