This is so bizarre, I’ve been on to apple, had 3 different senior techs call me - weirdly the calls keep dropping but I’m not giving up, I’ll try again later today.
Since I’ve carried out the force restart on the problem device, screen time/downtime has been half working. It doesn’t lock the social media apps at the time I have set but at some point over night they do lock because when I get up in the morning and check the phone, they’re locked and then they stay locked until the downtime clock allows them to open. (It’s currently 04:33 and they’re all locked).
as I said I’ve been on to apple, so far I’ve spent about 1.5hrs on the phone with them, screen sharing the device, going through all the settings - all of which checked out ok so I’m doing nothing obviously wrong - I knew this because I’ve got the exact same settings on our sons older model iPhone and screentime works perfectly on that device.
the second apple tech I spoke to was starting to conclude that it looks like a ‘glitch’ in iOS but then mysteriously the call dropped!
ill keep the thread updated with any new info as and when…