What else do you think is the problem???
Your schematic in post 13 may shown 0v in the meters both when the ULN is on and off (without pullup) but you can clearly see the grey square which shows the state of the pin and means floating, if you use resistors in place of the voltmeters and ammeter you will see that when you have floating at the output of ULN there is no current at all through the resistor.
You don't need any pullup in the display circuit, I don't know why you want to see a high level in the cathodes to feel reassured that everything is ok, suppose that ULM is replaced with a switch connected to the cathode , when you open that switch then the led can't turn on , the state of the cathode is irrelevant because there is no electrical path to ground and current can't flow and make it light.
Alex
Alex, if I leave it floating the simulation simulates it as low making the led matrix display light. That's what I want to confirm actually. If floating on the simulation (shows it as low) will be the same with floating in actual circuit.
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