We had a long discussion about this back in August/September 2016.
The driving dog has a very small offset, so one way is correct and it will drop in easily, but the other way will sort of fit if you really cram it in there. You can rotate the rotor as you go and feel that one way feels better than the other way, but the wrong way can be a fooler if you are not aware of it.
Next big question is, did you disturb the orientation of the 20 tooth drive gear in relation to the crankshaft? If so, your driving dog position may be wrong.
Last question, did you take the distributor apart? If so, the rotor position in relation to the driving dog may be wrong, 180 degrees off.
Follow the manual. Its all in there.