So how do I fix it?
It's hard to say. In an action where you set the accessible levels could be a timing problem. Somewhere you change the levelselect for more accessible levels. Sometimes you add more than one level, but only on slow devices. So you have to look where you set this variable if it is possible that it's set twice. Maybe in another event, or in the next tick.
It's also possible that is something complete different, some kind of bug. It's really hard to say.
If you provide a link I can look with my devices. If I have the same problem.