Passenger door opens only on second attempt

Hi all,

Lately when I come to a complete stop and unlock the doors from inside, all the doors unlock as it should.
But the passenger door you have to pull the lever twice for the door to open. This is the same from inside or outside.
When I try to lock and unlock the doors again, it works fine.
This is only happening for the front passenger, all the other doors work fine.

It seems something that after driving, then stopping, the passenger needs to pull the lever twice before the door will open.
The door does unlock properly, only not opening first try.

I have a 2010 UK Prius T4. It does not have navigation.
I tried the combination to program the door unlock/lock sequence with the gear position and lock buttons. But it has no effect on the UK version, unlike US.

Any help will be appreciated!
Many thanks.