I'm gonna go try the card on some other gas stations too and I'm also gonna see if I can fool the system and get cashback on cash withdrawal by doing it at checkout when I pay for my grocerys.
You will probably have this problem with several petrol stations. This is because the card is classed as a prepaid card rather than a debit card. I had a similar problem using the Revolut card when traveling through Europe. Some stations were fine and others weren’t. You can usually pay at the counter with it (after fuelling) but not at the pump (before fuelling)
It's been a while since I did much conversion but last I recall, it tended to be that you got a better rate if you had your card do the conversion (if using a credit card) than the bank ATM because banks are bastards.
I completely agree with Richy here. I ALWAYS ignore the conversion rate offered and pay in local currency. The visa or mastercard rate offered by Revolut is far better and they don’t charge a high ‘non sterling’ fee. On larger transactions such as hotel bills, the difference can be quite substantial. You were lucky they were the same rate on this occasion, but maybe try a few more to be sure.