BUG: Order is taken even if Incorrect Credit Card is provided

After testing many times, with the test credit card provided on your website. I came across a strange BUG.

This is the test credit card details:
Card number 4005 5500 0000 0001, Expiry 05/2023 CVC 123

Then, I intentionally tried incorrect credit card, to checkout a product to see what happens
Incorrect Card number 4005 5500 0000 0000, Expiry 05/2023 CVC 111

Then after checking out, I was returned to the same checkout form, with all the field values still there; but with a message “Payment Failed: Unspecific Gateway Error”.

I then repressed the checkout button, since the form data was still there. Then it said “your session has expired please login”.

I then went to “My account” and saw that this order was listed there; with that incorrect card.
I repeated this several times with incorrect card, but every time this error is shown but the order is still taken.

Thanks,

https://www.ads-software.com/plugins/woocommerce-fat-zebra-gateway/