For some reason in Unreal Engine 5.2 when I opened a Material Instance I was finding that the Material Instance Editor was opening in a docked tab making it impossible to see the viewport as you adjust material settings.
I have spent hour trying to find the preference to change this behavior.
Finding this thread has solved my issue.
I’m Really grateful to those who have posted here.
Editor Preferences
Use the search phrase: open asset
Set the following preference
General Appearance > Asset Editor Open Location: New Window (Default: Default)