My house was originally built so it could be easily adapted for people with disabilities. For example, there is wiring in the house to support the installation of a lift and the landings are wider than usual.
I'm not sure if this is part of the adaptations but the door latches don't close onto regular strike plates. Instead, they close onto these curious moving strike "plates". These strike units comprise a thin metal box which contains a rotating piece of metal that moves up when a door closes on it and then falls back down when the door is closed. The metal box is then affixed to into a recessed metal bracket in the door frame. They have the letters "CBuk" stamped on them which yielded nothing useful on a search.
These close slightly more easily than regular latches but otherwise create redundancy in the latch mechanism. The doors also have concealed spring-loaded door closers built-in.
A couple of these are now not working properly but I'm not sure whether to try to replace them with something more conventional or try and fix them or if there's even a good reason for them being there.