Thanks for the reply Jeordanis.
I tried to create a simple example file to illustrate the problem, but the simple version works fine. I created hair on a plane, exported curves as alembic, simmed in Houdini and brought back in an animation cache modifier before hair from guides and it worked fine.
On the actual character, I bring the simmed curves back in from Houdini and the orientation and shapes are wrong on all hairs. I can import the non simmed alembic curves and simmed curves into maya and blendshape between them without issue. What else about the curves or groom could cause this? In the AnimationCache modifier I can click Overwrite Input and set Display Fraction to 1 to display the curve correct at that modifier level. If I go to the Hair from Guides after that, it is incorrect again. I can unclick remember roots and click it back on and the hair looks right again.
In the simple plane test it works without all of this. There must be something different about this groom or the curves.
Before working with remember roots off and on again, I get the following errors in the maya script editor:
Ornatrix: Control [editGuidesOption1] doesn't exist
Ornatrix: Control [editGuidesOption2] doesn't exist
Ornatrix: Control [editGuidesOption3] doesn't exist
as well as
Error: Ornatrix: Cannot generate strand 150 because it has a non-existing guide dependency
(It does this for all curve, not just 150)
Any idea what this problem could be? Thanks.