I second Nevs Suggestion with Luminex, they work flawessly.
But I also have an ELC Node 4 in Use for my Travel Catalyst, which works also without any Trouble.
Make sure you have the latest Firmware (to be found @ the ELC Website) on the Node, as the older Firmware had a bug in the Artnet Protocol and did'nt make it possible to control Catalyst via DMX in.

I'm sure you've already checked, that your Ouput Universe is another Artnet Universe than your Input Universe. If not this can also lead to strange behaviour.

Good Luck

Rolf