So the plot thickens (semi).

I think I've spent more time than anyone in the world now reading about the various offsets for their threaded chainring options when installing the transmission power meter spide. this page on PowerMeter City is great but.......

My Epic Evo (which according to specialized is 52cm chainline). The bike came stock with the XX SL Eagle Crankset in 168mm Q Factor with a 32T 0mm offset chainring. (I even verified the Q factor with Sram via the serial number on my cranks) and so based on everything I've seen I should get the 3mm offset right?

Problem is, when I installed it all shifting went to hell, the installed chainguard no longer fit and so I swapped it for the 0mm offset (i'd ordered both) and whala, works perfectly.

Any idea why this is?

I even went to the local Specialized dealer and looked at a bunch of their EVO and Epic Evos with the new power meters already installed and they all have the 0mm offset threaded chainrings.