It is AccuLipSync

Absolutely great !  I didn't test MHs yet cos the latest MH Character Creator / Pixel Bridge update had some issues.
So you are showing here that CC4 Face mapping to MH works ... hmmm , so AcculipSync should work too , did you live link or FBX import ?

Hi Rob, how are you!
Ok - Are you getting no visemes at all?
I am using iC8 with a CC4 default base (CC3_Base_Plus), and it is working with a MetaHuman through Live Link to UE5.
On Playback in iClone, it makes the MetaHuman mouth move. 
Maybe a few things to review, as there are many possible ways of doing - Are you trying with FBX or LiveLink, and then with a CC3 or CC4 avatar, and then with a MH or a CC4 exported from iC8.

Oh yeah ROb - make sure you had the LiveLink Kit so that you replaced the FaceAnim_BP *after* you import in the meta Human. 
Sometimes I brought in the Meta Human after I put in the RL FaceAnim_BP, and it overrides it with the Qixel-MH one, which only works with iPhone's UE "LiveLinkFace" app.
RL's AnimFace_BP should work with both AccuLips and RL's "Live Face" app. 

FBX I don't know yet, I haven't tried that, if that's what you mean, where the FBX is not sending the acculips visemes over to UE5, but Bassline showed Blendshapes and maybe not visemes...I don't know. 

Live Linking AccuLipSync with CC4 to MH works for me  :



There are 3 Mappings , you have to activate the right CC4 mapping in the Anim Bp :



or here :

Hi Rob, Bassline and I are both doing it.
iC8 using a CC3 Plus, with an AccuLipsync speech performance, through Live link, to a MHuman, in UE5.
I can add in Blendshape, in this case a Digital Soul animation, so that it gives me face expression also to what I see in iClone.  
MH responds to Face Puppet, Face Key, and Accu Lips.
If not working try with a CC3 Base Plus from CC4, with the Extended Face Profile.  

@Rob , how do you know that Tony has a 3090 ? 😁