Cubase Elements hasn't got the routing of Cubase Pro.
The only way I found to get it to work was use KV ElementVST/VST3/AU/AAX just load Element plugin, click View (top right) then drag your instrument VST VST3 into KV Element and connect the ins/outs audio/midi.
Enable the EXT for sync like EZDrummer, EZKeys etc..

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