Reproduction steps:
1. Download and open the user-submitted project
2. Build and run the project
3. Open the Frame Debugger in the editor (Window -> Analysis - > Frame Debugger)
4. Select the connected device and press enable

Expected result: Three Draw Mesh calls appear under Canvas.RenderSubBatch
Actual result: No Draw Mesh calls appear for UI

Reproducible with: 2017.4.37f1, 2018.4.18f1, 2019.3.4f1, 2020.1.0a25, 2020.2.0a2

Reproducible on:
Windows standalone
VLNQA00175, Samsung Galaxy Note9 (SM-N960F), Android 10, CPU: Exynos 9 Series 9810, GPU: Mali-G72
VLNQA00230, Oneplus OnePlus6T (ONEPLUS A6013), Android 9, CPU: Snapdragon 845 SDM845, GPU: Adreno (TM) 630
VLNQA00322, Huawei P30 Pro (VOG-L29), Android 9, CPU: HiSilicon Kirin 980, GPU: Mali-G76
VLNQA00054, Xiaomi MI 4LTE (MI 4LTE), Android 6.0.1, CPU: Snapdragon 801 MSM8974AC, GPU: Adreno (TM) 330

Notes:
Drawcalls appear for UI when Frame Debugging in the Editor.