First Few Holes Inaccurate

I've had my x40 for a couple of years, but lately I've seen some odd behavior lately.

Recently, on several occasions, the yardages on the first few holes have been off by around 40 yards or so. And this is on courses I've played many times using the x40.

The first time it happened, I deleted the round after about three holes and started a new one, thinking it was just a one-off bug. But it happened again yesterday. Yardages were accurate once I got to the 4th hole, but they were off be around 40 yards on the first 3 holes. When I was standing on the greens, it still said I was around 40 yards out. I had to manually go into the scorecard setting and enter my score, since it never switched over on it's own to "scorecard mode".

Any ideas what's going on? I've stayed up to date with firmware/course updates. Is this what happens when the device starts to die?