New information here as well, after two full days of shops (22 stations), the Chevron system won't take the card anymore. Works fine everywhere else, but even the inside payment system won't accept it. (Yes, there's over $1000 on the card, and it is declined for a $2 purchase). Paypal can't help, since on their end it's fine.
I will continue to swipe at the pump, take a photo of the "declined" screen, and then pay cash inside - which I KNOW they don't want, but their guidelines created the situation.
Interesting that every other gas station with this MSC still allows gift cards. Guess I'll stick with those, and give the Chevron's a rest for a while!