I adjusted my lineup 2-3 times so I know I set it. However, it says I forfeited. Has there been a bug? Anyone else have this problem?
Go to "set lineup" for your next match. At the top of the orders page is a drop-down box that allows you to choose your lineups from previous matches, and you should be able to see the lineup in question.
As for why it was a WO lineup when you're certain you set a valid one: Did you have to refresh the page at any point before setting the lineup? Sometimes this clears the lineup, and sometimes setting the lineup from a mobile phone can cause a slew of problems as well.
Just throwing ideas out there, but this might be better suited for the bugs forum.