Wise messed up and won't resolve it!
I and my partner each transferred a large amount of money (from the sale of our UK home) to Australia. Wise guaranteed our rate provided we provided documents in time. We did this. I got an email 2.5 days later saying my transfer had been cancelled due to a system error on their part and to redo it. My partner got a similar email (though his didn't mention that it was Wise's fault). We were both left at the mercy of the new, lower rate. This lost us over $1000. 
Wise's initial response was that it would be resolved immediately and we would be compensated. Luckily we didn't wait, because 4 days later we have been told they need to check whose fault it is. We know its theirs because they have all our documents and when we did the new transfer they used those and sent it through correctly.
We chose Wise because they're trusted. We won't use them again, they're unreliable and don't try to resolve things when they've messed up. Very bad customer service!