Using Virtual CC Number

I've been using Citi virtual credit card numbers & even got the .01 occasional charge several months back, but it was about to expire so got email from FP to update my billing info.

I updated it with new exp date & changed amount to $12 but FP doesn't seem to want to take it. I'm getting error message "Credit Card charge failed. Please try again later or contact Customer Service."

Is FP not allowing virtual numbers anymore. How do they know it's virtual #?

Is anyone else able to use virtual numbers?

I'm pretty sure I read that they're no longer accepting virtual cc numbers.

I've read that, too-- that they are ruling out a lot of virtual and prepaid cards that used to work. As to "how"-- I really don't know, but I think I've read that at least some virtual cards can be identified as such by the first few digits. (Second hand info, not confirmed.)