How is it that my son is able to bypass his screen time limits of 1 min and play for 5 hours?

Sometimes non-technological solutions are the best way to overcome issues with technology.

Take the device away from the child for an extended period of time.

I suggest one month, minimum, the first time.

After a one-month 'time-out', if the child can once again demonstrate the ability to consistently obey parental rules and device restrictions, and act responsibly 100% of the time, the device may be returned.

However, if the child again fails to abide by parental rules and device restrictions, even once, the device is again forfeited, this time, at least twice as long as the first time.

I suggest that if there is a third violation, they lose use of the device permanently, or until they turn 18, leave the home, and have employment to pay for both device and cellular service from their own income.

If the child absolutely needs a way to call home, there are inexpensive (non-Apple) flip-phones available for a one-time purchase price of $20 or less from prepaid carriers. They also require the purchase of a pre-paid limited-use short-term service plan, starting as low as additional $10 per month or so.

These inexpensive flip phones lack the ability to easily use social media and make it more difficult, but not impossible to send lengthy texts using the T-9 keyboard on a flip-phone.

One advantage of prepaid service is that short-term plans (as few as 30 days) are available with a specified limited number of call minutes, MB or GB of data, and texts. Perhaps make the child pay for both the flip-phone device and the cellular service. That is another way to restrict unlimited phone calls, web access, and texts at reasonable cost.

Yes, "Unlimited" monthly and annual prepaid cell service plans are also available, but in this case, that may only encourage further abuse of parental rules and restrictions. Most pre-paid carriers allow 'Bring Your Own Device' to use a previously-purchased Apple iPhone with their pre-paid service.

If this is a shared-custody situation, you really need to work with all parents and step-parents involved to enforce these restrictions until the child can once again demonstrate the ability to consistently obey parental rules and device restrictions, and act responsibly 100% of the time.

(Yes, essentially the same reply I provided in two other recent Apple discussion threads about children creatively overcoming intended parental device and app restrictions.)