A weird boot opening 'problem'

[Fastpedaller]

Here's a weird thing with our Ford Ka+ (the 5-door that very few know about)...... The boot latch failed a few weeks ago, and I replaced it. It took some careful adjustment to get it opening and closing, combined with the panel gaps being correct. I achieved it, but it's now got the same issue our Daughter's car (same model) has always suffered from.
There is an internal boot release switch alongside the headlight switch - If this is pressed, the latch can be heard releasing. Going to the rear of the car, the tailgate is still held in the 2nd position of the latch. Pushing the internal switch again, or for an extended period won't open the tailgate, but pushing the keyfob button will release the second latching. I'm aware all latches (including door and bonnet on all cars) have 2-position latching for safety reasons. When the tailgate is fully shut (ie both first and 2nd latches 'active', If the keyfob switch is pressed, it releases the tailgate fully - either from outside or within the car.
I don't understand why the solenoid receiving the 'open' voltage isn't working the same, irrespective of whether it's getting the command from the keyfob or the internal switch.
It previously worked with the old latch until it failed (and was sealed so it couldn't be fixed)

 

[bikingdad90]

Having a wild guess; some sort of anti theft measure? If you theoretically can get to the internal switch but have no key, could you be theoretically stealing the contents from the boot? Granted bit of a weird thing to do.

My more logical guess is something to do with the latch having a mechanical operation and a radio operation, something to programme/change in the ECU to make the internal switch fully release?

 

[Fastpedaller]

My understanding is that 12v 'triggers' the unlatch (viewing the insides of the broken one) by turning a worm gear connected to a gear wheel - I can't understand how or why the operation would be different depending on switch or keyfob. Maybe as you say the difference is generated in the ECU? The previous one worked fine until it didn't after 9 years. No real problem (as long as the new one doesn't fail completely) and our Daughter's car has always had the same issue (only 6 months difference in age).
The tailgate was a problem when we bought our car (new from dealer), and it needed slamming like we were trying to break it - there would be a message continually flashing up "tailgate open". The dealer said it wasn't a problem (and there was no remedy) so after we'd driven home I adjusted the latch keeper a few mm, and all was well for 9 years. If I hadn't achieved it, I'd have been asking the Dealer for our money back - It was driving us crazy.