Reproduction steps:
1. Open the attached “IN-97974“ project
2. Open the “SpriteAtlasBug.unity” Scene
3. In the Project window, go to the SpriteAtlasBug folder and select the “Atlas_tokens.spriteatlas” to open it in the Inspector
4. Make sure the Build Platform is set to Android
5. Set the Override atlas format to "RGB Compressed ETC2 4bits"
6. Click Pack Preview
7. Observe the error in the console and the corrupted preview result

Expected results: The format is supported, atlas in the preview is not corrupted and there is either no error or a less confusing error in the Console
Actual results: The "Unsupported source texture format (7) in ComputeNextMipLevel" error is shown in the Console and the atlas is corrupted in the preview

Reproducible with: 6000.0.9f1, 6000.0.22f1, 6000.0.45f1, 6000.1.0b13, 6000.2.0a8
Not reproducible with: 2022.3.60f1, 6000.0.8f1

Reproducible environments: macOS 15.3.2 (M3 Max), macOS 14.7.1(M1 Max, by reporter)
Not reproducible environments: No other environments tested

Workaround: enable sRGB in the Sprite Atlas setting inside the Inspector

Notes:
- If the issue does not reproduce, try:
a) change the Atlas Padding (there are three options: 2, 4, 8)
b) remove/add a Sprite from the “Objects for Packing” list
c) enable the “Texture Read/Write” option for the Sprite Atlas
- Deleting the Library makes the issue no longer reproduce