Conditional Access query

[maxrebo]

We have a conditional access rule setup so Staff accessing 365 in school (on a School IP address) aren't challenged for 2FA, every now and again devices that have a School IP address get challenged for 2FA. I cant seem to work out why this is? Its just at random times. Everyone doesn't get it at the same time, the devices are the same.

Has anyone experienced this?

 

Regards

[NegativeKillDeath]

You should be able to check the sign in logs on entra and see what triggered the MFA challenge. 

[ITGuyNW]

Is the school ip address part of a range further up?