Right, so apparently this is related to (a (timing)bug with) ZeroFX. (Again ZeroFX was way more expensive than simply using Amazon’s converter and the initial charge was off by a few euro’s - ugh. :()
When ZeroFX settles, this won’t be reflected in the account balance yet. So on your end everything looks good, no negative balances, etc - but on bunq’s end: you have a negative balance. This can happen more often if you keep a low margin balance on the account dedicated to you online purchases.
I’d suggest to bunq that these notifications are sent out with a delay, so that everything has the chance to update properly and shows the right info to the customer :) Otherwise it’s very confusing, lol.