Alt+LMouse on a group visibility icon behaves differently depending on wether the group is open or closed.
In my scenario I have multiple groups and one layer outside the groups.
Alt+LMouse on the group vis. icon when the group is open makes all groups and layers (including the ones inside the group itself) invisible, rendering only the folder layer itself visible, which in itself cannot contain anything.
I believe that the expected behaviour should for that scenario is that it works like when replicating the steps while the group is closed: everything else except the content in the group is rendered invisible.
On a separate note; it seems as Alt+LMouse on Eye icon cannot be used on the selected layer.