According to instant-support, lurkr removes the role of the previous level when a user levels up. The solution it gave was to configure a section of the dashboard "Level-based Role" which I can't seem to find.
I want to make it so members get to keep the role of their previous levels. Obviously I can do this by manually giving the new roles permission to have what I them to have but keeping the previous roles would be like hitting multiple a lot of birds with one stone.