State of Charge in battery shield reporting 255?

I’ve got the battery shield hooked up and I’m trying to monitor the state of charge. I understand it’s supposed to be a value from 0-100.

It all seems to work just fine until a point where it jumps to 255 and stays there until I reset the photon. I don’t even have to unplug power. The red led onboard indicating full charge doesn’t come on either. I suspect the issue is firmware related.
Here’s the graph showing the jump.

This thread discusses the same issue but with the sparkfun battery shield. It appears to have been resolved with a firmware update to 4.4. I’m on 4.9 now.

Did you ever get an answer to this? I’m getting a voltage of 5 and an SoC reading of 255…