How to reproduce:
1. Open the attached project "UIDoubleDrawCalls.zip"
2. Build and Run a Development Build to a mobile device
3. Navigate to the Frame Debugger window (Window -> Analysis -> Frame Debugger)
4. Enable the Frame Debugger and select to profile the mobile device the build is running on
5. Navigate to the Draw Mesh calls by following the path: Camera.Render -> Drawing -> Render.TransparentGeometry -> RenderForwardAlpha.Render - > RenderForward.RenderLoopJob -> Canvas.RederSubBatch

Expected result: There is only one Draw.Mesh call just as when profiling the Editor
Actual result: In the mobile builds there are two identical Draw.Mesh calls instead of one

Reproducible with: 2018.4.36f1, 2019.4.29f1, 2020.3.13f1, 2021.1.14f1, 2021.2.0b2, 2022.1.0a1

Reproducible on:
VLNQA00332, Samsung Galaxy XCover4 (SM-G390F), Android 9, CPU: Exynos 7 Quad 7570, GPU: Mali-T720
VLNQA00381, Xiaomi Redmi Note 8 Pro (Redmi Note 8 Pro), Android 9, CPU: MediaTek Helios G90T MT6785T, GPU: Mali-G76 MC4
VLNQA00099, Google Pixel XL (Pixel XL), Android 10, CPU: Snapdragon 821 MSM8996 Pro, GPU: Adreno (TM) 530
VLNQA00052, Xiaomi MI MAX (MI MAX), Android 7.0, CPU: Snapdragon 617 MSM8952, GPU: Adreno (TM) 510
iPhone XR (13.4.1)
iPhone 8 Plus (14.4.2)

Notes:
- To see the correct calls in the Editor the Game window must be changed to a Portrait aspect ratio
- The mobile device also has to be set to portrait mode
- In the 2018.4 this seems to also reproduce in the Editor as there are two Draw Mesh calls in the UGUI.Rendering.RenderOverlays -> Canvas.RenderOverlays