It appears as though mekanism universal cables as well as pipez cables (and possibly other mods) do not connect to the exterior of a compact machine from the mod compact machines 4. The intention is to transfer power from inside the compact block to outside of it. It can be replicated by placing a mekanism universal cable next to the output of a compact machine block containing an energy tunnel.

I cannot reproduce this in testing, so I'm assuming it has been fixed.

What version of the modpack are you running? This SHOULD be fixed as of version 0.23 i believe?