Never figured it out, mine still work in both Spark and Bolt. I think it's likely a software or hardware bug. If you have a good relationship with your local dealer and you're still within your 5 year/60k powertrain joke, I mean warranty (sorry, I'm still bitter about my local service center experience), maybe they'll fix it and not try to steal your kidney.
Personally, I only use Sport mode on a rare occasion when I'm fooling around. There's really no novelty and I quickly turn it off. This is coming from someone that drives hard too (979 Hard launches/accelerations in the past 30 days, ha) take that for what it's worth.
Edit: first image link was bad