Updating a mesh that has been changed in code

Hi all, I have a script that animates a mesh by changing its vertices and texture. It works in the Unity "Game" window. But when I preview the build on my Oculus Go, I can see the original mesh and texture at the beginning of the scene, but it never updates.

I wonder if this is because the Oculus-Unity source code doesn't re-load a mesh's data on every frame by default. Maybe I need a line in my code that triggers the Oculus renderer to re-load this mesh. But haven't figured out how to do that yet. Any help appreciated!