Using Flex with Ebay

Ordered 5 T-shirts on eBay and checked out on normal Monzo card.
I then flexed the amount to go over 6 months.
The next day as items were dispatched I was charged per item as they were sent, rendering flex null and I’d now end up charged twice

Details to reproduce
Order a few items under £30 on a site like eBay, pay for full amount by debit card, then flex the amount on Monzo App, over the next few days as items are sent out you are charged per single item and still under your flex obligation.

Android 12
Pixel 4A
App Version:


Did you get charged for the initial payment & then flex it? Has that payment bounced back & been refunded? So you’ve basically been charged twice at the moment?