Don't worry about your deposit. Before you started the mixing process, ChipMixer gave you a session token. You can restore your session with this token. I hope you saved it. But the thing is, those session tokens are only valid for 7 days, and after that they expire. They can be extended, but you need access to the site to do that. Since these are extraordinary circumstances (the site being down), I am sure the support can help you here.

@ChipMixer
What happens with a user's deposit if the site doesn't come back online 7 days after the session expires, but he couldn't use the service or extend the session due to the downtime?