+1Lift the clocks off. they come out with a little force and check the cable is plugged in the back of them properly.
and if that do not help, check grounding wires on LCD wire loom cables + ECU grounding point (the one with ring terminal that goes to negative terminal to ECU).
The wacky "full digit" syndrome is either LCD data connectivity issue or grounding/noise.
ECU is not the suspect.