The Guide contains no information with respect to VOD/ TV-Series etc.
You are obviously using an Android system with a slow processor.
If you can access VOD from your PVR, you enabled "Include VOD" in the Potato setup. you should redo the setup with this disabled.
You could try "EPG Shrink" setting, in the PotatoTV config settings. I dont know if it would help since I have never enabled it.
Upgrade to a faster box, is the recommended way to go. Benefits are enjoyed in all aspects of use, (and the cost is minimal).
/kens