I have looked into the issue. From my findings, tournaments with check ins enabled still show up in the widget. During the check in period, a participant can not check in nor forfeit via the widget.
As it turns out, users that have signed up for a tournament through the widget are automatically checked in when the check in period begins just the same way manually entered participants via the Challonge website are. Because of this, there is no way I can check in a participant via the plugin.
The only changes I have made for the next update (1.1.4) include a forfeit button during the check in period but not once the check ins have been processed. Additionally, I have added support for check ins where participants may check in if they are not already, which as I mentioned, doesn’t happen.
Since you mentioned that tournaments do not show up if they have check ins enabled, I suspect you have one or more of the statuses checked in the widget settings. If you save the settings with all of them unchecked, it will not filter out any of the statuses, including “checking in” and “checked in”.
Please let me know if this helps or not. Thanks!