Confirm Your Gift not working

I’m trying to send a gift card via email and when I reach “Confirm your gift” page the BUY button just changes to BUY NOW then to BUY again, but BUY is greyed out. In a few seconds the button is blue again, but no purchase happens. I tried to make a purchase with a mobile phone (enough funds there) and tried writing it off from Apple ID balance. But nothing works. Please help.