How to reproduce:
1. Open the “IN_70903” project
2. In the Build Settings make sure the Standalone (could be other than Android) Platform selected
3. In the Player settings select the Android Settings tab
4. Observe the Additional Compiler Arguments

Expected result: "-warnaserror+:CS4014" is in the list
Actual result: "-warnaserror+:CS4014" is not in the list

Reproducible with: 2022.2.20f1, 2022.3.22f1, 2023.2.15f1, 6000.0.0b11
Not reproducible with: 2021.3.36f1, 2022.2.19f1, 6000.0.b12
Fixed in: 6000.0.0b12

Reproducible on: Windows 10 Pro
Not reproducible on: No other environment tested

Notes:
- Issue is not reproducible when Android Platforms is selected in the Build Settings
- User also reported one more issue “Also all "platform tabs" in the Player settings seem to show the Additional Compiler Arguments of the current active platform (build target), not what matches the selected "platform tab"“. A separate bug report will be made regarding this issue since the affected versions are different from the current bug.
- Reproduction might be inconsistent. To make reproduction more consistent try opening and closing the Project Settings window ~5 times. Also changing between Build Target could trigger reproduction if it doesn't reproduce after following the steps.