While deleting the "TextMeshPro" Asset folder from the project window, a new instance of "TMP Importer" window is created every time even though another instance is already open, refer the attached video.

Steps to repro:
1. Create a new project with 2D Template
2. Hierarchy > right-click > 3D Object > Text - TextMeshPro
3. TMP Importer > Import TMP Essentials
4. TMP Importer > Import TMP Examples & Extras
5. Project > Assets > TextMesh Pro > delete

Actual Result:
On deleting an existing "TextMeshPro" Asset folder, a new instance of "TMP Importer" window created every time.

Expected Result:
Should update the already opened "TMP Importer" window instead of creating a new instance of the window

Tested with Unity version: 2020.1.0a17, 2019.3.0f3

Package version found: preview.1 - 3.0.0, preview.1 - 2.1.0, 2.0.1, 2.0.0, 1.4.1, 1.4.0

Package version working fine: 1.3.0

Environment:
Windows 10 and macOS 10.14