Received this email from Walmart today:
Thank you for being a loyal Walmart+ member. We recently fixed an error that caused a delay in charging the fees for your monthly Walmart+ membership for 1 or more previous months. Unfortunately, as a result of this fix, charges for all missing payments were processed earlier this week, along with your recent monthly renewal payment, resulting in multiple charges to your payment method on file.
We understand that this is not an ideal experience. We will be refunding the additional charges for the previous months for which we missed taking your payments. The funds will be returned to your original form of payment within the next 7-10 business days, and we sincerely apologize for the inconvenience this may have caused. You can still expect to see your next payment come through on your next scheduled renewal date.