Magnetometer gets stuck at near-magnet levels

[JScott]

Sometimes after I pull a device out of a Cardboard v1 enclosure, the ambient magnetometer magnitude stays at its peak for a while before dropping, seemingly arbitrarily. The ratio doesn't get affected much so it still detects triggers but it can be falsely triggered as "stable" which allows triggers when there shouldn't be that tend to mess up the up/down state.