Reproduction steps:
1. Open the attached project "ReproProj"
2. Build And Run on an Android / IOS device
3. Observe the background around the Player when the Scene loads

Expected result: Background is transparent
Actual result: Background is black

Reproducible with: 2022.2.9f1
Could not test with: 2020.3.46f1, 2021.3.22f1, 2022.2.12f1, 2023.1.0b10, 2023.2.0a8 (“Assets\Scripts\UI\CompatibilityTag.cs(12,92): error CS8124: Tuple must contain at least two elements.” and a bunch of other errors)

Reproducible with devices:
VLNQA00332, Samsung Galaxy XCover4 (SM-G390F), Android 9, CPU: Exynos 7 Quad 7570, GPU: Mali-T720
VLNQA00325, Samsung Galaxy Note10 (SM-N970F), Android 12, CPU: NOT FOUND, GPU: Mali-G76
VLNQA00318, Oneplus OnePlus 7 Pro (GM1913), Android 11, CPU: Snapdragon 855 SM8150, GPU: Adreno (TM) 640
VLNQA00231, Samsung Galaxy A5(2017) (SM-A520F), Android 8.0.0, CPU: Exynos 7 Octa 7880, GPU: Mali-T830
VLNQA00231, Huawei HUAWEI Mate 20 Pro (LYA-L29), Android 9, CPU: HiSilicon Kirin 980, GPU: Mali-G76
VLNQA00494 - iPhone 14 Pro Max, 16.3.1 iOS
VLNQA00358 - iPhone 12, 14.1 iOS
VLNQA00392 - iPad (9th generation), 15.0 iOS
VLNQA00310 - iPad Pro 12.9", 13.4.1 iOS

Testing environment: Windows 10 Enterprise 21H2

Notes:
* Does not reproduce in 2021.3.18f1
* Render Over Native UI is checked for the project, but the packaged app still submits a solid black base color to Android or IOS when drawing