[Edit late 6/2/19: Many hemp and CBD websites lost their payment processors on 5/31/19. Early reports from some of the sites tied this to the 5/31 FDA public hearing on CBD. It seems that the problems were more specifically related to the payment processing company Elavon shutting down CBD processing. It is unclear at this time whether this really had anyting to do with the FDA hearing.]
The FDA held a public hearing on May 31st to get input on how to regulate the booming CBD industry. Published reports describe a very wide range of views expressed, ranging from CBD advocates and scientists to anti-marijuana spokespersons. One interesting fallout of the meeting is that credit card processors dropped many CBD companies overnight. A product that was easily ordered on May 30th with a credit card was now unavailable from many sites unless you mailed a paper check.
This sort of thing has happened before. At least one site reported that they are switching banks and expect to accept credit cards again within a few days (using a bank headquartered in Asia). Some sites had no information (as of June 1st) and the buyer simply got a cryptic error message after entering credit card information. This happened to me on one site.
CBD products are now available in many brick and mortar stores, so if you are running low try these sources. In addition to CBD shops I have seen it advertised in Bed, Bath and Beyond and in Earth Fare supermarkets, for example. You should expect that most online sources will have convenient ways to pay within a week or two.