LCD in the centre is the old type. There are three things I'd look at: firstly, the motor connector under the left chainstay. Unclip it and make sure it's properly connected, then zip-tie it out the way of where you can't kick it; Secondly, the torque sensor connector and the wire from the torque sensor, which is screwed to the back of the chainwheel. Check that the cable isn't damaged and that the connector is in good condition; Thirdly, take the LCD off and clean all the contacts.
If none of those fix it, you have to take off the torque sensor and clean it. There are some very thin slots that light has to pass through, which you will see when you have it off the bike.