# Issue with avatar facial animation (Mouth and Eyes)

**URL:** <https://forum.convai.com/t/issue-with-avatar-facial-animation-mouth-and-eyes/6607>\
**Category:** Unity SDK\
**Created:** [October 21, 2026, 2:13pm UTC](https://forum.convai.com/t/issue-with-avatar-facial-animation-mouth-and-eyes/6607 "2026-10-21T14:13:17Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![demetris.loizou](https://yyz2.discourse-cdn.com/flex004/user_avatar/forum.convai.com/demetris.loizou/32/4286_2.png) [@demetris.loizou](https://forum.convai.com/u/demetris.loizou)\
**Post date:** [October 21, 2026, 2:13pm UTC](https://forum.convai.com/t/issue-with-avatar-facial-animation-mouth-and-eyes/6607/1 "2026-10-21T14:13:17Z")

</div>

### What do you need help with?

Bug report

### Installation method

UPM

### Issue area

Lip Sync / Facial Animation

### Impact

Major - a core flow is broken, but I can keep working

### Unity version

6000.4.10f1

### Convai Unity SDK version

Convai 4.6.1

### Target platform

Windows

### Where does it happen?

Custom scene

### Short summary

Weird Avatar Facial Animation Issues (Mouth and Eyes)

### What happened?

Hey Convai team

I’ve been having a weird issue with my project since yesterday. Everything was working fine before, but now my avatar sometimes stays with its mouth open during idle, or its eyes become half-closed while talking and sometimes stay closed even during idle.

This happens both in Unity and in the built version. Restarting sometimes fixes it temporarily, but the problem eventually comes back. Unity doesn’t show any errors, and I’ve also tried different internet connections, but nothing seems to help.

The only change I made last week was adding an asset to the avatar’s hands, which follows the CC\_Base\_L\_ForearmTwist bone using a Parent Constraint component. I’m not sure if this could be related, but I thought I’d mention it just in case.

Any idea what might be causing this?

Thanks!

### I checked the relevant documentation, resources, and similar forum posts before posting.

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### I confirm that I did not include API keys, tokens, passwords, secrets, private character data, private conversation logs, or customer data.

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