Fixes#10154
### What was happening:
1. Click "Import" in dropdown -> Dropdown stays open
2. Click "Select file" button -> Two events occur:
- Button tries to open file dialog
- Click event bubbles up, reaches dropdown, dropdown tries to close
3. These competing actions cause the first click to fail
### Fix
By closing the dropdown immediately when clicking "Import":
No competing event handlers are active
The dropdown is fully closed before any file selector interactions
The open() function from useDropzone can work without interference
91b7d2855e