Linux KODI TV box

Hi – don’t know that I am in the right place as this forum seems to be for people who know what they are doing – I don’t however. I recently purchased a called The Megasmart TV Box which runs on Linus \9\’\js \linus API Network portal portocol) and has Kodi, among other options. I have Rogers 60mbps, and 200 gigabits of bandwidth. 70% of the time when I turn the tv on the “stream is temporarily unavailable”, or the screen is blank, or when it does work the stream is constantly breaking up. When I took it back to where I got it (they don’t do refunds), and they plugged it in it worked perfectly. They claim it must be my internet. I tried moving my router to right beside the tv. That made to no difference. Is this the nature of the beast or am I doing something wrong? Thanks