Roku Slow to Load Channel on xfinity App

I'm new to Roku and streaming apps; been streaming xfinity app for about 2 weeks using a Roku Streaming Stick Plus. I'm getting used to it but have one major complaint; when changing channes, a lot of times it takes a long time for the channel to load. My experince has been from 3 seconds which is fine to upwards of 30 seconds + and sometimes the video is pixelated for the first few seconds once the channel loads.

Trying to figure whare the problem is, the app, Roku internet or somewhere else. Any suggestions?

Thanks