I have 3 teen boys, 13,16 and 19. The 13 and 19 yr old have been very understanding and compliant, especially the 19yr old who was disappointed he couldn't see friends for his birthday but accepted it.
The 16 yr old though...
In my experience 15/16/17 is the sweet spot of teen rebellion, thrill seeking and general lack of empathy (varies per child obvs).
To be fair he's done really well up until the last couple of weeks. All his mates are now calling him, they seem to be meeting up in the park or wherever they hangout. Yesterday he went out for 'a walk' and didn't come home for 5 hrs.
Like the OP I'm not sure what to do about it. I can reason with the other two but him not so much. He's in that teen mindset where transgressions and hassle from the old folk is totally worth the pay off. I know this because I remember being like that myself at his age!
I could go the usual route of removing privileges - phone/internet/xbox but that seems counter productive because the less he has to do at home the more he'll go out.
Neither is the answer to this stopping him ever leaving. He's not in a prison and I'm not prepared to get into a physical confrontation with a 16 yr old boy - anyone who thinks that would be a good idea probably hasn't spent much time with teen boys.
Short of having the army on the streets a total lockdown was never going to work for an extended period with all young people. If anything I'm surprised he managed 2 months following the rules before we reached this point.
The best tool for compliance was novelty and fear and that's wearing off for a lot of people, especially teens who are famed for a poor grasp of mortality (their own and others). We live semi rurally and are fortunate not to know anyone who is ill or has died. Our LA seems to have a low number of reported cases for a very large area.
I have no idea how to continue making it real for a self centred teenager who so far is lucky enough to not be experiencing death and illness in people he cares about or have it directly affect him.