Your question is vague and oxymoronic (no offence in using that word).
You state that the digitizer is not responding to touch but then that it is? If you mean you are pressing the screen so hard as to put pressure on the LCD, then stop. That’s too much pressure.
Purchasing from eBay has a “buyer beware” clause right? Which means, either this is a defective used product or a mis-labelled defective new product. If you wish to repair it, use the teardown guide to take it apart and purchase a replacement screen to test it on.
The digitizer which registers the touch could be the issue. Also be aware, a non-touch responding tablet doesn’t necessarily mean a bad digitizer, but can also mean a bad board issue. The digitizer is clearly glued to the front glass so it will take some time to replace the digitizer. Alternatively, you can replace the entire “display assembly” which includes the glass, digitizer, LCD, front chassis.