Are all the cards the same part number? If not, they might be Jeppesen specific, which I believe takes the Jeppesen version of the programmer instead of the Garmin one. See this FAQ from Garmin.
Also, there was an update to the flyGarmin app
recently, so make sure you have the latest installed.
There has also been an issue
with the update permanently, irrecoverably trashing cards, that Garmin insists is a bad card or you have to “take it to a dealer” cause their software can’t format or repair the card after their software trashes it.