It seems like the MAC address on your tablets might be changing, which can cause connectivity issues, especially on secure networks like your school's Wi-Fi. Here are some steps you can take to troubleshoot and potentially resolve this issue: 
Verify MAC Address Changing:
 
- Obtain True MAC Address: Check the physical MAC address of the tablet. This can usually be found in the device settings. Verify this MAC address with what your school's system is recognizing. Troubleshooting Steps:
- Network Settings: In the tablet's Wi-Fi settings, ensure "MAC randomization" or "MAC address spoofing" options are disabled.
- Static MAC Address: Some devices allow you to set a static MAC address. Try setting a...