Nobody helped a damsel in distress? Chivalry is dead I guess.... I will give it a try...
From what I have read - if you over tighten a clearo onto a battery or mod - it is possible the pin on the battery or mod can get pressed inwards. Not saying you did this - just saying that this can happen. I think saw this fixed on Youtube with an MVP, the guy used a small flathead screwdriver and worked his way around the pin on the battery/mod, pulling it ever so slowly and gently outwards -- don't remember who the poster was. But - I would suggest the following troubleshooting tips before you start that process:
1) Do other clearos work on the Zmax without issue? Is the depth of the pin on the working ZMAX clearos less than the EVOD? Might be the EVOD then... If not, then maybe the connection pin/rod on the zmax has been pushed in too far.
2) Does the EVOD work on an ego or other battery without issue? if yes - might be an incompatibility issue with the Zmax and the EVOD - I dont have a Zmax -- so, I cant say for sure, or that it worked fine for me or anything - you might find a better answer asking someone who owns the same Zmax as you. If the EVOD doesn't work on anything - then it's the EVOD - maybe a bum coil? or poorly made coil - I think it was Rip Trippers, talked about how like 2 out of 10 Kangertech coils were bunk - and it ticked him off

-- but then again, it could of been someone else - I watch a lot of Youtube!
3) Are all the connections clean of any juice spills? I had an ego charging once, and it gave me a fast flickering red-green, when it should of been fully charged and a solid green. Upon inspection - I found that the threads of the charger somehow got a little juice gunk on it. _ I unplugged the USB, cleaned up the threads on the charger with a alcohol swab - let it dry and it was a solid green again when I used the charger again. If the Zmax has some kinda ATTY checker program in it - maybe its going into protection mode? am just guessing here - I am no expert. But try wiping the threads of the Zmax with a alcohol Q-tip and see if they are clean?
lastly- Having rebuilt a few of the kangertech coils on the EVOD/PROTANK 2 -- I can tell ya, the only thing holding that pin in place is the pressure from the insulator and a little friction from the coil wire. -- if you pull that pin too much on the EVOD -- it's like uncorking a bottle -- so be careful.
Hope something I said helped -- if not, at least I tried to be a valiant hero?!?!?