I have found that the box with the credit card payment type always reverts to a corporate card with surcharge, even when I set it to the personal card with no charge. So I fill in all the boxes, and then the very last thing I do is reset to personal card with no charge, before hitting <make payment>.

it seems to automatically switch to a card with surcharge - I got caught once, didn’t bother chasing them as the amount was small, but now I always double check.