Apply blend shape same frame

Hi!

We've got a system for changing character's faces using blend shapes. When we enter a dialogue with a character, we enable the character model singleton object, and set all the correct blend shapes on the face mesh:

Code (csharp):

1. // approximately what I'm doing
2. var model = GetCharacterFromPool();
3. model.skinnedMeshRenderer.SetBlendShapeWeight(faceIndex, faceValue);
4. model.gameObject.SetActive();

The problem is that these blend shapes doesn't take effect until the next frame, so there's a single frame visible where the character has the wrong face, before it suddenly snaps to the next face.

The blend shape is set as a part of the normal Update loop.

Is there any way for me to force a skinned mesh renderer to instantly apply the current blend shape?