I would contact the manufacturer, if it is still under warranty, as it may be a hardware problem.
Also, if it is say a bad app, virus or malware a 'factory reset' won't fix it, as that tries to leave personal data on the device, which would also leave the problem. A "Hard Reset" might, however, fix the problem. If it is a software one. If it is hardware, as mentioned before, then that won't help.
NOTE: Doing this will clear 'all' the data on your tablet, so it is suggested you not choose this option unless you have to, or aren't worried about losing anything on the device.
Be sure you back up any data you want to keep, to a computer or cloud account, before doing the reset.
To "Hard Reset" the tablet...
1. Make sure that the...