How to reproduce:
1. Open the attached project
2. Make sure InputField (TMP) has "Hide Mobile Input" enabled
3. Build & Run on mobile devices
4. Tap on Input field and write some text
5. Double tap on input field to select all text

Expected result: All the text is selected
Actual result: Selection highlight appear where the hidden mobile text field is positioned but without the text

Reproducible: 2019.4.20f1, 2020.2.3f1, 2021.1.0b6 2021.2.0a4

Reproduced on:
VLNQA00340, Samsung Galaxy Note20 Ultra 5G (SM-N986B), Android 10, CPU: Exynos 990, GPU: Mali-G77
Google Pixel 4, Android 10, CPU: Snapdragon 855 (SM8150), GPU: Adreno (TM) 640
VLNQA00269, Samsung Galaxy S10e (SM-G970F), Android 9, CPU: Exynos 9 9820, GPU: Mali-G76
VLNQA000125, Google Pixel 2, Android 11, CPU: Snapdragon 835 (MSM8998), GPU: Adreno (TM) 540

Not reproducible:
iPhone 12, A14, 14.3 OS version