MGCB Editor "Add > New Item..." dialog missing type options & Create button disabled

Prerequisites

I have verified this issue is present in the develop branch
I have searched open and closed issues to ensure it has not already been reported.

MonoGame Version

3.8.4.0

Which MonoGame platform are you using?

MonoGame Cross-Platform Desktop Application (mgdesktopgl)

Operating System

macOS

Description

See that the "Type" options are missing, and that the "Create" button is disabled:

Proof of also running MGBC 3.8.4.0:

Steps to Reproduce

Open MGBC Editor: dotnet mgcb-editor
"File > Open..." to open my project's Content.mgcb file
Right click a folder, "Add > New Item..."
See the dialog with no "Type" values to select, disabled Create button

Minimal Example Repo

No response

Expected Behavior

I have to downgrade to MGCB Editor 3.8.1.303 to show the expected behavior. To downgrade:

Update dotnet-tools.json

diff --git a/Metrovan/.config/dotnet-tools.json b/Metrovan/.config/dotnet-tools.json
index 0e0d981..0e2496f 100644
--- a/Metrovan/.config/dotnet-tools.json
+++ b/Metrovan/.config/dotnet-tools.json
@@ -3,31 +3,31 @@
   "isRoot": true,
   "tools": {
     "dotnet-mgcb": {
-      "version": "3.8.4",
+      "version": "3.8.1.303",
       "commands": [
         "mgcb"
       ]
     },
     "dotnet-mgcb-editor": {
-      "version": "3.8.4",
+      "version": "3.8.1.303",
       "commands": [
         "mgcb-editor"
       ]
     },
     "dotnet-mgcb-editor-linux": {
-      "version": "3.8.4",
+      "version": "3.8.1.303",
       "commands": [
         "mgcb-editor-linux"
       ]
     },
     "dotnet-mgcb-editor-windows": {
-      "version": "3.8.4",
+      "version": "3.8.1.303",
       "commands": [
         "mgcb-editor-windows"
       ]
     },
     "dotnet-mgcb-editor-mac": {
-      "version": "3.8.4",
+      "version": "3.8.1.303",
       "commands": [
         "mgcb-editor-mac"
       ]

Run dotnet tool restore

❯ dotnet tool restore
Tool 'dotnet-mgcb' (version '3.8.1.303') was restored. Available commands: mgcb
Tool 'dotnet-mgcb-editor' (version '3.8.1.303') was restored. Available commands: mgcb-editor
Tool 'dotnet-mgcb-editor-linux' (version '3.8.1.303') was restored. Available commands: mgcb-editor-linux
Tool 'dotnet-mgcb-editor-windows' (version '3.8.1.303') was restored. Available commands: mgcb-editor-windows
Tool 'dotnet-mgcb-editor-mac' (version '3.8.1.303') was restored. Available commands: mgcb-editor-mac

Start MGCB Editor: dotnet mgcb-editor, then open my project's Content.mgcb file

Which demonstrates the expected UI:

Resulting Behavior

Again, this is after I upgrade back to MGCB Editor 3.8.4

Files

No response