This issue has been reported for Firefox on mobile. It may happen with other browsers.

The switches will actually operate is you click on the top corner of the status you would like to set. For example, if an option is currently set to off, click on the top corner of the switch box (the one on the on side). The switch will move to the on side.

There is no fix for this issue but it's very easy to get the hang of it and users with this problem have reportes good comments with this workaround.