Web proxy/url filter dont work

[hvacguy (Shaun HVAC)]

I little reading could help.
You can search the forum for more help.

Proxy + URL Filtering + mobile phones = KO

Hello everyone, I have installed my first server with ipfire and I am using the proxy + URL filtering, it works very well in wireless mode or with the wired network with computers. However, the problem is with mobile phones, despite the transparent mode of the proxy being configured, mobile phones connected via wifi have no restrictions, internet is accessible without restrictions. Is there something particular to configure for smartphones? Thank you for your help and have a good day