Restarting the app inside Homey should do the trick. 
There is an older thread here. This version of the app is a re-write of @glennsp ’s original app. Some of the guides in the old thread might still be relevant, but future questions and requests should be posted in this one.
Please don’t hesitate to let me know if anything is unclear. I’d be more than happy to assist you, and get your ovens back on track in Homey! 
