Very odd stats for Pushover

I have my phone set up on both hubs as a notification device via Pushover. On the main hub I noticed that my run time stats are actually negative! Very strange.

Thoughts?

The device seems to functioning perfectly.

Is it a case of them getting so high they flipped into negative (due to the data type?) I've had the opposite with one of my battery devices. When it needed recharging, it sent what was obviously supposed to be a -1 but presented as 255! Which was amusing but did mean that the usual battery minder did not flag it as low battery! I had no idea until I pressed the button and it didn't work