Not my usual topic for a video, but I thought it was a worthwhile topic. I have been using all sorts of smart locks from many different manufacturers, over all the various hardware formats and communication protocols. This is the first smart lock that has not been a disappointment.
I enjoyed your review of the U400 Smart Lock from Aqara. I have also just recently purchased the same U400 lock to replace my Aqara U100 Smart Lock which was having issues. So far everything is working great. 
Thanks for a great video.
I have the 400 lock installed and working well.
I have UWB enabled on my iPhone, but can’t work out how to enable it on my wife’s iPhone!!
Please can you advise?
Many thanks 
to set up the lock for my wife, first she made the aqara account and from my account i invited her to be an administrator. she then accepted the invitation.
at that point, we thought it wasn’t working because it showed no devices. However, then i noticed that when she setup the account it created a new ‘my home’ so now there were two ‘my home’ configurations. The default one was the new one without devices and the other was the existing one. I switched to the existing ‘my home’ that had the correct devices and then deleted the one that was set up with the account.
so my only advice is to see if there are more than one configuration on your wife’s phone and if she just needs to change configurations.