Setting default homepage with managed preferences for guest accounts.

I am trying to set the default page for Chrome, Safari, and Firefox for guest accounts in Sierra.
Under the managed preferences for Internet Configuration I have it set as user level enforced with the url. I have also created one for safari that is user level at every login with url.
I have the Contents of new tab set at 0 to show homepage and Contents of new window set at 0 to show homepage. In safari, it will show the homepage when I click on home it shows he correct homepage. I couldn't find any examples anywhere to do this for any of the 3 browsers.
Any help would be appreciated.