What do you mean you can't find it? DigiKey alone has 128,206 of them.
Why do you need that exact part? It is not really necessary in first place, but if you want it, just place any TVS you can find in a compatible package.
Also, measuring TVS diodes with a multimeter is useless. They are used in reverse breakdown direction and multimeter usually don't provide enough voltage in diode mode. What you are observing is the forward voltage, which is fine. Your TVS is likely fine and does not need replacement.