This is a great question and we see it a lot. Really, it highlights just how opaque FX fees are in the industry, particularly with large institutions.
It's important to notice that we're the only product that combines a fixed fee and zero FX markup. Banks are charging you a fixed fee, but marking up the FX rate by 1-3% typically. So you're actually paying 8 EUR explicitly + 1-3% hidden fee which, in total, is a (very high!) variable fee.