How to turn off Limit Ad Tracking - Greyed Out

On iOS 11 Limit Ad Tracking is automatically turned off by any FiOS users, and probably many other network providers. Disconnecting from these will allow you to turn off Limit Ad Tracking, however reconnecting will turn it back on and grey it out again.

This normally only occurs if you have (or had) a company email address on the device. If that is the case there is no way around it other than to permanently delete the account.

However, you probably shouldn't be visiting sites that use ad tracking. You are essentially selling your soul and your privacy to the highest bidder.

Its very odd this one but I did this:

Go to Settings> iTunes and Appstore. Select your email address and SIGN OUT.

Now go back and the Ad Tracking button can be toggled on or off.

Note: if you then go and sign back into to the App Store it will be toggled back on and greyed out again!

I am experiencing the same problem just on a iPod touch 6th gen

There is somet in your settings that's not allowing it. This process helped me: settings>general>reset>reset network settings

Check restrictions - do you have the "advertising" setting to not allow changes?

Another possibility is a security profile is controlling it. This might be the case if you have a company email account on your phone. Having an MS Exchange account gives the account administrator a lot of control over what you can and cannot do with the phone.