How to reproduce:
1. Open the attached "LockFileTest" project and setup perforce version control on it
2. Open "Boot" Scene from Assets > Scenes folder
3. Make sure that "Verify Saving Assets" in Preferences > General is unchecked
4. Mark Add and Submit the PolybrushMesh "Assets/Mesh/PolybrushMesh-1752.asset" to perforce
5. Open P4V with the same Workspace as used in the Editor
6. Find the "PolybrushMesh-1752.asset" file and in the right-click menu select "Change Filetype"
7. Add the Exclusive Checkout option (+l) and press OK
8. Submit the "PolybrushMesh-1752.asset" file
9. Open a different Workspace in P4V
10. Get the latest version of "PolybrushMesh-1752.asset" file
11. Check out the "PolybrushMesh-1752.asset" file
12. Get back to Unity Editor
13. Open "SampleScene" Scene from Assets > Scenes
14. Save (Ctrl-S)

Expected result: the Assets are saved successfully without any infinite import loops
Actual result: an infinite import loop occurs

Reproducible with: 2019.3.0a6, 2020.1.0b9, 2020.2.0a11
Not reproducible with: 2018.4.23f1, 2019.3.0a5
Could not test with: 2017.4.40f1 (project errors)

Notes:
-This also reproduces when instead of saving in the 14th step a new Assets is created or an old one is deleted or submitted.
-The infinite import loop is usually stopped and an error is thrown except from 2019.3.0a6 to 2019.3.0b1 where no errors are thrown and the loop goes on seemingly forever