Video streaming issue

We purchased an MXQ Pro TV Box about one month ago for use in our lounge. It came preinstalled with Netflix, Showbox and Kodi. About one or two weeks ago, we began to experience issues with Showbox when watching a program or movie. It began to buffer every one or two minutes, and sometimes restarted the movie. This actually begins after 19:00, and happens every evening. We also installed Showmax, and it has similar problems. Our internet speed is 4 mb/s. Is there an issue with the applications themselves or our internet connection? Any assistance would be appreciated.