USB connectors can go bad==could be on plug end or tablet receptacle. An 'easy' fix is to try a new USB cable or a different charger/cable combination to see if it works.
My grandson's HISENSE 7 PRO has the internal connector problem. Taking the tablet apart to solder in a new connector is not a sound approach, since the work would have to be done by a professional and would cost more than a new tablet. So we looked for a workaround.
If we plug in the charger cord and put a prop under the connection which holds it at an angle of 135 degrees to the tablet, connection is indicated on the face of the tablet and charge occurs. A pain, but we've bought a year+ time this way. Might work for you.