ms family account screen time limits not working

I too had struggled to get this feature to stick properly to one of my three kids. Two were working fine, one not. All identical hardware, so it was highly irritating one was out of alignment to the others. 

Reinstalled the OS on his PC, still no joy. Removed him from family group, tried everything on the suggestions and they all were useless. 

What I noted was that the time limit that I setup was being ignored but there was still a time limit. Instead of 1.5 hours, it was 4 hours per day. No matter what I set it to, it remained. However, if I turned off limits on his account, instantly the setting on his PC was aware that the limits were removed. When I imposed them once more, the same 4 hour limit (rather than the 1.5 hour limit) was turned back on. 

I concluded that in my case, the time limits set on the website were being ignored or overruled by something on the PC. The feature was linked though, reporting functions worked, and clearly when I switched the time limits off, they applied so no issue with the account itself. 

I searched around a bit more, and saw this bit of advice:

Delete the Parental Control Settings in the following path:

• On the Start screen, type C:\ProgramData\Microsoft\Windows\Parental Controls and press Enter.

Delete the folder and files under this location. When the user logs in again, it will force a check with the settings stored online and redownload the settings. 

The reason this didn't get fixed when I did a reinstall of the OS was that I kept files/settings and it never got wiped in the OS re-install. 

As soon as I did this, the correct time limit and schedule was finally applied to my son on his PC. No idea why it got stuck, or why it would never overwrite, but it cleared it. Hopefully future adjustments to the time limits and schedule will work as normal from now on.