Reproduction steps:
1. Create a new Universal 2D project
2. Create Cube GameObject (GameObject > 3D Object > Cube)
3. Change all Position and Rotation fields values
4. Open Grid and Snap Settings in the Scene window
5. Make sure that Cube GameObject is selected and press “Copy from Active Object” button
6. Observe Grid Transform Rotation values

Actual result: Incorrect values are displayed in Rotation fields
Expected result: Rotation values match GameObject Rotation values

Reproducible with: 6000.4.0a3
Couldn’t reproduce with: 2021.3.58f1, 2022.3.68f1, 6000.0.60f1, 6000.2.8f1, 6000.3.0b7 (No Grid and Snap Settings)

Reproduced on: Ubuntu 24.04, macOS Sequoia 15.4 (M4)

Note: Issue is also reproducible with right-click > Grid > Align to Active Object Rotation