Sounds like a electrical issue. Tue latch is momentary, so it releases then go back to latch. If it is staying open, that means thsy it is getting hung up or not resetting.
I would open the trunk ( if possible
) and press the trunk release on the fob. You will hear the latch do its thing. If not, then possibly fob battery is dead .....unlikely or there is a glitch in the matrix.
If you are gonna be at the commack show we will be there to check it out.