The "Block on Startup" feature operates to prevent attempts to disable the Mobile Fence app before the device has fully booted. However, on lower-end devices, when running resource-intensive apps like games, the Mobile Fence service may temporarily restart during the resource optimization process, which can unexpectedly trigger the "Block on Startup" screen.

To prevent this issue, you can change the settings as follows:

1. Battery Optimization Exclusion Settings → http://mobilefence.com/kms/15509528
2. RAM Optimization Exclusion Settings → http://mobilefence.com/kms/18749382
3. Perform "Memory Optimization" before running games if possible → http://mobilefence.com/kms/81716040