There appears to be a different code path inside Obsidian for clicking the toolbar icon to open the Search pane vs. using the Hotkey. I have observed that, after a fresh launch of Obsidian, clicking the icon does not clear the previously entered query, while using the hotkey does. This may be important.
I have found a reliable way to repro the issue (in restricted mode, no plugins):
Activate the Search panel
Execute a query
Set sort order to Modified time (new to old)
Navigate away from the search results (e.g. back to the File Explorer)
Quit Obsidian
Relaunch Obsidian
Use the hotkey to trigger the Search function
Observe that the sort order has reverted to alphabetical
I found this bit of code in app.js which I assume is directly or indirectly responsible for changing the value of the dropdown.
Ok, I can reproduce. I have the feeling this is tied to the changes made for deferred execution.
When using the command/hotkey to invoke global search view (and global search view hasn’t been idealized already), Global Search view is initialized with ALL default parameters and nothing in the search box.