The "reset" button on the support settings don't change the value on the dropdown (none vs sphere in the tip section for example), but it changes the behaviour, so it doesn't udpate the GUI.
Let's say I have the value "sphere" set. I click "reset". The dropdown still shows "sphere", but the support will not use the sphere, so it uses a "none" setting.
To use the sphere setting I have to change the option twice: first to "none", then to "sphere".
It is not possible to reset it if it is under the edit support screen