Hi-hi! I'm so glad you've been enjoying it!
I'm not sure exactly what would be causing it, but I do have a few things you could test. First, try fully deleting the authentication file in the program folder and then fully authenticating again. If that doesn't help, trying it with a new port might (I had this issue when I used the Cult of the Lamb Twitch Integration, because it was using the same port and causing an issue for some reason.) You can find the port info in the settings towards the bottom if I remember correctly.
If that also doesn't work you're welcome to send me some of the log files either on Twitter or via Gmail (RhapsPerhaps for both) and I'd be happy to see if any errors pop out.
It also could just be Twitch being weird. I've seen a lot of things connected to Twitch stop working lately. (A stream I watched today had half their automated redeems just break.) So if that's the case, hopefully it will clear up soon!