Speedtree Textures missing in IOS

I’ve just started trying to push Speedtree assets to a build on an ipad Air 2. I’m building from a mac pro in 4.7.
On local launches, the assets work fine. All my other assets (build in Maya) work fine. On the ipad I feel like i’m missing a setting somewhere for speedtree. The assets come in with the grey checker texture, like this:

I just made a very simple asset in Speedtree 7.1.1 with 120 tri’s, 2 textures and 3 materials.
I’ve gone through the doc here: SpeedTree | Unreal Engine Documentation
I can’t seem to find any discrepancies with my assets. No warnings from it on build.
This is my first IOS app. I’ve been going through the doc here: Materials for Mobile Platforms | Unreal Engine Documentation

Any help would be appreciated.

Well, for the person who runs into this and can’t find the answer… here is what it was for me.
If I removed any of the default connections speedtree makes in the material (even the ones that Mobile Stats doesn’t flag like SpeedTreeColorVariation to base color) and make it simple like this:


I had just not been removing SpeedTreeColorVariation… This is what it looks like on default import: