We had a similar problem previously. Contacted Sat King and was told I must be pushing the Mode button by mistake. This was on the opposite side of power button so not feasible.
Finally contacted people we purchased from and he contacted Sat King who called me and suggested I may have been inadvertently activating the button below the power button when pressing power button. This seemed a more likely scenario than the previous advice.
Since then have been very careful when pushing power button and have no further problems.
Hope you are able to get it sorted.