JSiu-Dev Before doing that, do you mind checking if the key “OpenLinkPreview” is false after you’ve unchecked the “Open external links in preview” setting? The preferences file is located at ~/Library/Preferences/com.kagi.kagimacOS.RC.plist (or ~/Library/Preferences/com.kagi.kagimacOS.plist if you’re using the Beta), and keys are in alphabetical order. With space bar preview (it's "true" / meaning checked here):
To reset all settings, Orion menu -> "Reset Orion..." or Command+Shift+Delete, then this checkbox will reset all of your settings: