Google:
From the Android TV Home screen, scroll down and select Settings .
Under "Device," select Apps.
Under "Downloaded apps," choose the app you want to remove.
Select Uninstall OK.
You mention devices. Do you have many devices which are connected to the wi-fi?
It could be duo to a old router which is overloading with many signals in your home.
Check your router settings and make it rest sometimes (power).
This issue can only be device related or there is really something wrong with your internet. There are many factors which could be causing this issue, but first thing what comes up in my mind:
Call your ISP provider and let them check if your internet has any package loss or any kind of...