I tried this service today to mix around 50 USD.
I sent to the wallet provided and once deposited, I selected to withdraw all.
I imported the keys and I get around 48 USD, meaning I lost around 4% of the money sent.
Today upon creation of chips, one transaction got delayed because mempool grew up quickly. It left our transaction with much lower fees than others and all new transactions had higher and higher fees.
We have bumped the fee for it and it is confirmed now. Please check your wallet. Private keys are already imported so Electrum should notice confirmation. If that's not a case, try to recover session using session token and reimport keys.
If you still have a problem, please contact us by email and provide deposit address and/or session token, we will help.