@Inthedark

I would first try and check to make sure that the device was within the specified power required by the fans to function. I would also make sure that all your wires have been connected securely and that nothing has come loose when putting it back into the box.

Lastly, double and triple-check the specifications for your fans. It is not uncommon to see HD fans with smart capabilities or an RF controller embedded.

You may also instead of going through trial and error, wait for a device that is meant for ceiling fans :) 

Kasa KS240: Smart Fan and Dimmer Control

This was announced at CES and should be slated to come out later this year as long as everything goes according to plan and no problems are found throughout the test.