shop payment bug

I found a bug when purchasing subscription time through the shop. Too my knowledge this is the only thing I tried it on. When purchasing the year subscription I was prompted to enter a password to complete the transaction. Being myself I wanted to make sure I chose the correct payment method (It was paypal) so I pressed the back button on the browser and it just reloaded the webpage and completed the transaction without needing the password. Luckily with the help of support this was fixed. I went to try again with the correct payment method (A new card) I did the same thing as a test. It reloaded the page this time asking for the card ccv and expiration date. I click next and it processed without needing a password. I don’t know if this is a known bug or not.