Battery Meter Exhibits Strange Behavior

I hope someone can help answer this question about strange beahvior of the battery meter/gauge in my 2015 Volt Premier Edition.

After a full charge, the battery meter reads 43 miles of range.

I begin to drive and the meter reduces each mile I drive as expected. Until...I hit 39 miles.

Then in the next .25 miles or so the meter drops from 39 - 30.

Then at the 30 mile mark, it stays at 30 for about 6-7 miles of range. From which point it goes back to normal metering by going down a mile for every mile driven.

It's bizarre. And it's consistent, repeatable, and always occurs.

A) Does anyone have a similar experience?
B) Does anyone know why it would be doing this?

Thank you,
Volt Fan in Oregon