I switched to the old experience and can't get the new one back

Switching to the old version is set up to last for a single meeting, so it will automatically revert back after about an hour. 

However you can also manually revert it back by doing the following:

1

Open up your Whereby room.

2

Click on the Lock icon to the right of your URL bar. 

3

Select Cookies.

4

Highlight the whereby.com cookies, and click Remove.

This will log you out of your account so you'll need to log back in. After doing that you should be directed to the new meeting experience when you join a room!