How to reproduce:
1. Open the attached “swizzle_import.zip“ project
2. Select the “AfghanTree_B_005_Billboard_Normal“ texture
3. In the Inspector change the Compression to “High Quality“
4. Above the preview, select “A“ (alpha channel) and observe

Expected result: Alpha channel of the texture is seen
Actual result: A solid white color is seen

Reproducible with: 2022.3.40f1, 6000.0.14f1
Could not test with: 2021.3.41f1

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

Note: The issue did not reproduce when applying platform settings.