Replaced broken screen- it won’t sense touch anywhere on it

I've done a lot of iPhone X screens and generally when one part, either the display or the digitizer, doesn't work, it's usually been because I didn't get the connector seated in just right. The issue you're seeing apparently happens often enough that they felt worth mentioning it in the step where you disconnect the digitizer.

• To re-attach press connectors like this one, carefully align and press down on one side until it clicks into place, then repeat on the other side. Do not press down on the middle. If the connector is misaligned, the pins can bend, causing permanent damage.
• If any part of your screen doesn't respond to touch after your repair, disconnect the battery and then re-seat this connector, making sure it clicks fully into place and that there's no dust or other obstruction in the socket.

Some of the things I've run into include trying too hard to push the connector in place, thus damaging either the receptacle or the plug, getting it misaligned just enough that it seems to be seated but isn't really, or damaging the flex cable so it doesn't work.

You'll want to follow their advice and open the phone backup, unplug the battery and disconnect the digitizer. Just to reiterate, it's this connector here.

While you have it open, check both sides of the connector with a magnifying glass and a bright light, looking for bent or broken pins. Bent pins can sometimes be straightened out with fine tip tweezers. While you're at it, go over the length of the cable looking for tears or severe bends that could damage the circuit traces inside.

Once you're happy everything is okay, clean both sides of the connectors with 90% or higher concentration of isopropyl (rubbing) alcohol, give it a moment or two to dry then plug the digitizer back in, heeding the cautions about clicking it into place.

After you've reconnected the battery, test the touch screen and see if it's working. If you still have no joy, try plugging the old screen back in to verify whether the digitizer still works on that. If it does, that would argue for a defective replacement screen; otherwise something else may be going on with the phone.

Give these suggestions a try then come on back and let us know what you find, for better or worse. Success stories are always appreciated, and we can usually learn something when things don't go right.