Had the weirdest experience trying to use Hilton GCs at the Hilton Naples today. The cards would not go through for $50 each, but when the front desk person tried running $20 charges, the cards each went through twice. But not a dollar more on each. So I was able to get $40 from each gift card. I had just gotten these a month ago. Reading above it seems like it's the same issue some others have above of these being run as the wrong kind of gift card.

Had no issues using GCs for the full amount at a different property in Naples earlier this year (Inn at Naples, Tapestry)