Steps to reproduce:
# Open or create a project
# Go to "Window" ->"Package Manager"
# Go to the "My Assets" section
# If you don't have any assets please download them (for example "Food pack - 3D Microgames Add-Ons")
# Click on a "+" on the import button
# Select the imported package item in the list
# Observe that its details become displayed in the detailed view section
# Try to resize the window by dragging mentioned section

Expected result: Window UI always should be the same.

Actual result: The window becomes distorted. Added screenshot and video in the "Attachments" section.

Reproducible with: 2023.2.0a23.

Not reproducible with: 2023.1.4f1, 2022.3.4f1, 2021.3.28f1.