@B Wylde if you use Intune and the one from ZhoumingDuan-MSFT didn't work you can have a look at the InteractiveLogon_MachineInactivityLimit
MaxInactivityTimeDeviceLock (Already mentioned by ZhoumingDuan-MSFT)
https://video2.skills-academy.com/en-us/windows/client-management/mdm/policy-csp-devicelock#maxinactivitytimedevicelock
InteractiveLogon_MachineInactivityLimit
If you are using hybrid joined devices, a GPO may overwrite the setting. In this case, you would either have to take this from the GPO or apply the setting via the GPO.