Hey sorry I missed this thread.
It could very well be an Arnold issue...I know there's a couple of kinks in their tyFlow implementation and I can't remember if they've been fixed and/or what versions of Max they've been fixed for.
The simplest solution would be to render as meshes, instead of instances. Mesh mode will bake down the mapping information instead of keeping it as an instance override. That said, another quirk of the Arnold implementation is that it may try to render tyFlow as instances even if you have it set to meshes...if that's the case, bring your particles into a tyMesher object and render the tyMesher - Arnold can't render tyMesher data as instances so that's a way to override that behavior.
VRay's implementation doesn't have those issues, but I understand if you can't use VRay...at least this gives a workaround that should work.
It could very well be an Arnold issue...I know there's a couple of kinks in their tyFlow implementation and I can't remember if they've been fixed and/or what versions of Max they've been fixed for.
The simplest solution would be to render as meshes, instead of instances. Mesh mode will bake down the mapping information instead of keeping it as an instance override. That said, another quirk of the Arnold implementation is that it may try to render tyFlow as instances even if you have it set to meshes...if that's the case, bring your particles into a tyMesher object and render the tyMesher - Arnold can't render tyMesher data as instances so that's a way to override that behavior.
VRay's implementation doesn't have those issues, but I understand if you can't use VRay...at least this gives a workaround that should work.