Don't do that connection frankly. ICE trains are often delayed and you'll probably miss the night train. I'd recommend a 45 min-1h buffer in case. Check the ponctuality of your train here : https://www.zugfinder.net/en/start
On which train are you planning to travel ? I'd recommend this itinerary from Düsseldorf :
- ICE Düsseldorf Hbf - München Hbf 14:45 - 19:27 3€ optional reservation on ÖBB
- break for delays, to buy some snacks, etc.
- NJ München Hbf - Padova 20:09 - 05:02
Platforms and other useful infos are available on bahn.com or DB Navigator app but last-minute changes can happen.
Yeah a 9 min change in Munich is definitely more than risky.
But if you try it and there is a small delay, then talk to the conductor that you booked the nighttrain. If the delay is not too big, sometimes the nighttrain waits for connecting passengers.