On clicking "Material" Shader Dropdown in the Inspector window then it causes editor to throw EndLayoutGroup error, refer to the attached video.

Steps to Repro:
1. Create a new project with URP template
2. Project > right-click > Create > Material
3. Project > Material >Inspector > Shader > Click

Actual Result:
EndLayoutGroup error thrown on Clicking Material Shader Dropdown in the Inspector window

Expected Result:
Shader Dropdown list should be open gracefully

Reproducible in:
2021.1.0a2

Working Fine in:
2021.1.0a1

Environment: Ubuntu 18.04 LTS

Stack trace:
EndLayoutGroup: BeginLayoutGroup must be called first.
UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&) (at /home/bokken/buildslave/unity/build/Modules/IMGUI/GUIUtility.cs:189)