If you're having frame rate issues while on a PC, you should first try going to Settings > Power and Sleep > Additional Power settings and make sure you're on a high-performance option.
If you're using the streaming program XSplit, make sure that "Special Optimizations" have been disabled for the source you're using for Jackbox Games.
If you're using Windows 10 or later and still experience Frame Rate issues, you should make sure that you disable the Xbox DVR feature. Here is a tutorial on how to do that.
Disable any non-standard built-in / bundled software that may be attached to your video card such as the Nvidia overlay or AMD software capture and streaming tools.
Additionally, make sure that you have the latest driver updates installed.