How to reproduce:
1. Create and open a new project
2. In the Hierarchy select the "Main Camera" Game Object
3. In the Inspector spam click the cube icon in the top left corner of the panel to open and close the "Select Icon" dropdown
4. While spam clicking observe the console output

Expected result: the console doesn't throw any errors
Actual result: a "MissingReferenceException" error is thrown

Reproducible with: 2020.3.33f1, 2021.3.1f1, 2022.1.0f1, 2022.2.0a10
Not reproducible with: 2019.4.37f1

Reproducible on Ubuntu 20.04
Not reproducible on Windows 10

Error:
MissingReferenceException: The object of type 'HostView' has been destroyed but you are still trying to access it.
Your script should either check if it is null or you should not destroy the object.

Note: after throwing the error the opened dropdown will remain open with no content inside of it after having clicked away to close it