OK so here’s an update on the front door situation.
As mentioned previously, there was a mechanical issue that was causing the latch to jam such that it could not be opened from the inside or outside.
It turns out the issue is with the size and positioning of the hole in the strike plate.
If the door was closed with enough force, the dead-latch plunger would get stuck inside the strike plate, and the lateral force on the plunger would prevent the latch from retracting.
A temporary fix has been implemented in the filing a notch in the strike plate (the strike plate needs to be replaced for a permanent fix anyway) so that the dead-latch plunger can fit through.
This is NOT how the latch is meant to work, but it allows for somewhat normal (though rough) operation.
For a permanent fix the strike plate will need to be replaced and positioned properly.