There have been many different makes and models put on the market which seem to work OK, but also many which have a glitch or two. We need to learn what the glitch is to overcome it or deal with it. In some cases, models have a Ground Balance control. Many, many average hobbyists would like to keep things simple and not learn how to Ground balance, thinking a turn-on-and-go model will work just fine. Unfortunately, 'glitches' in design can cause some serious in-the-field performance failures so we need to make sure all settings are done to our advantage.
Many models can be tough to ground balance. What is important is to know the limitations which may apply to a model and deal with them. Also, to be clear in which mode you are adjusting the Ground Balance and searching. With most of the Tesoro models, even since the Bandido series with a 10-turn manual GB control to the present 3Blank Planet said: