Reproduction steps:
1. Open the attached "repro_IN-85999" project
2. Open the "Assets/OutdoorsScene.unity" Scene
3. In the Hierarchy, select the "Sky and Fog Volume" GameObject
4. In the Inspector, in the "Visual Environment" Component, make sure that the "Sky Type" parameter is unchecked (this will help to see the issue clearly)
5. Enter the Play Mode
6. Observe the Game view

Expected result: There's no flickering
Actual result: There is some visible flickering on the ship

Reproducible with: 6000.0.23f1
Couldn’t test with: 2021.3.44f1, 2022.3.50f1 - Not able to open the project due to compilation errors

Reproducible on: Windows 10 (22H2), Windows 11 (10.0.22631) (user's)
Not reproducible on: No other environments tested

Notes:

• Not reproducible in Player
• The issue is not visible when the Editor window is unfocused
• Other upscalers (FSR2, STP) don't exhibit this behavior