Under Page Edit -> Restictions, when restricting page operations to groups, group entry text box does not validate that a user is a member before applying the group restriction. This can lock users out of their own pages. Instead, it should display an error same as 'Group not found' such as 'User must be a member of this group'.

To replicate, used 2.2 std and created new space. Added new group of which user is not a member, edited homepage of new test space and under restrictions went to group picker. Test group was correctly not displayed, only default groups. However the group name the user does not belong to can be entered manually without using picker menu, and is accepted.

David