First of all, (and sorry if this is obvious, but it has confused a few people before now...), when you go to the Live Services / Speed cameras menu, the top right icon should say "Disable alerts" (because that's what happens if you tap on it now).
If it says "Enable alerts" then you've actually got it switched off!
Next, if you go to Live Services / Speed cameras / Alert settings then there should be a long list of camera types (mine has 11) and every one should have a little loudspeaker symbol beside the name. Tapping on each one in turn should give you a menu page with three choices... 1. Always warn, 2. Only warn when speeding, 3. Never warn.
In order to test if things are working, I suggest to select "Always" for EVERY camera type in the list.
The next menu page gives you a choice of warning sound for each camera type. Check they are not selected to "Silence". Try changing a few of them just to make sure everything has been set up right.
Next, the cameras do not show up on the "Browse map" screen, only on the navigation display.
One tip... if you know the location of a camera near you, you can use the "Demo route" feature to do your testing, rather than actually having to drive past a real camera.
And finally, TomTom's own camera data is not the best... You don;t say where you are from, but in the UK it's pretty poor. I'd suggest you look into one of the third-party alternatives if there are any in your country.
Those will use the TomTom's standard POI warning system, so are actually more flexible as you can set the warning distances yourself and have far more useful alerts using real voice recordings that tell you the speed limit in force as well as what type of camera is ahead.