Help! 9 year old son dodging Microsoft Family screen time limits

[Grrrrrrrrrrrrrrrr]

Can anyone help?

9 year old son got his first laptop for Christmas. I set up Microsoft Family and applied limits on screen time, what sites he could access, etc. But he can override this by either:
(a) adding a new local user account to the laptop, within which he doesn't log into his Microsoft online account, or
(b) using his usual account and logging out of his Microsoft account.

I now see hundreds of complaints about this on the Microsoft forums. Does anyone know how to fix this issue? Any trustworthy 3rd party apps I can use if Microsoft is really this shit? I'm actually really fucking annoyed with them as I don't have time to research this for hours! 😡

I went to an internet safety chat at my Dcs school last year. It was eye opening. Did you know that the AVERAGE age a child first sees porn is 10 years old? And parents were giving real life examples of their child having no unsupervised access to the internet but another child shoving a porn video in front of their nose on the way home from school.

We were also warned that DC can get round almost every parental control that exists. And know how to wipe the history etc etc.

I have 2 DC who are ND. I am fully prepared to be the bad guy/parent who turns the screens off. They know how much they are allowed. They shout and argue when I say stop. And later they come and hug me and apologise (sometimes, not always)

We've had safety internet talks too. And screen safety talks - i.e. what it does to your brain/dopamine etc.

This
Plus you can buy routers that deny access to certain devices at certain times of day e.g. tp-link

I had one but it stopped working really quickly - but had it long enough that just the threat of replacing it now works. I could turn off access to all devices immediately from my phone:)