How to reproduce:
1. Open the user-attached “arfoundation-samples-main.zip” Project
2. Build and Run the Project
3. In the Player select “Face Tracking” and then “Face Regions”
4. Allow the application to access the Camera
5. Observe the screen

Expected result: Once a face is visible on Screen, Gizmos appear (Face Tracking is working)
Actual result: No Gizmos are visible due to the Frame Rate (Face Tracking is not working)

Reproducible with: 4.2.10 (2021.3.35f1), 5.1.2 (2022.3.20f1), 6.0.0-pre.5 (2023.2.11f1, 2023.3.0b8)

Reproducible with these devices:
VLNQA00531 - OnePlus OnePlus 11 5G (CPH2449), CPU: Snapdragon 8 Gen 2 (SM8550), GPU: Adreno 740, OS: 13
VLNQA00520 - Galaxy S22 USA (SM-S901U), CPU: Snapdragon 8 Gen 1 (SM8450), GPU: Adreno 730, OS: 14
VLNQA00517 - OnePlus 10 Pro 5G (NE2213), CPU: Snapdragon 8 Gen 1 (SM8450), GPU: Adreno 730, OS: 12
VLNQA00411 - Galaxy Z Fold3 5G (SM-F926B), CPU: Snapdragon 888, GPU: Adreno 660, OS: 11
VLNQA00341 - Note20 Ultra 5G INT (SM-N986B), CPU: Exynos 990, GPU: Mali-G77, OS: 11
VLNQA00122 - Samsung Galaxy S9 (SM-G960F), CPU: Exynos 9 Series 9810, GPU: Mali-G72, OS: 10.0.0
Google Pixel6 Pro - OS: 14 (by user)

Testing environment: Windows 11 (22H2), Windows 11 (10.0.22000) 64bit (by user)

Notes:
- Couldn’t test with iOS, “Undefined Symbol” errors
- The user project is based on Unity provided ARFoundation samples from: https://github.com/Unity-Technologies/arfoundation-samples
- Issue can be artifically reproduced by limiting framerate using Application.targetFrameRate.
- As the user noted, Frame Rate should not cause Face Tracking to no longer work, this is visible in the User Projects “ARCoreFaceRegionManager.cs” Scripts Update() function, where the Frame Rate is being limited.