It's ranges from very difficult to impossible to track an identity before, through, and after the mixer, but seeing if a transaction merely came from or through a mixer isn't all that difficult. That's why Binance probably detected that you used a mixer, yet I'd doubt they have the capabilities to tell where the money came from before it was sent through the mixer.  It depends also on the obfuscation tactics used by the mixer. They are not all the same! Yomix has low fees and that's great, but my gut tells me, and I hope this is wrong, but could this be an instance of "you get the level of security you pay for?" Would I be better off using a higher-fee mixer that perhaps tumbles to the excess and uses a wider range of time delays. Not as fast, more expensive, I guess all just different products to choose from.