Steps to reproduce:
1. Create new Unity project using Universal 3D Template
2. Create any GameObject (e.g. GameObject > 3D Object > Cube)
3. Open Animation window (Window > Animation > Animation) and dock it next to Console tab
4. Click “Create” button in Animation window to create new Animation Asset
5. Add Transform Position Property in Animation window
6. Add few Keyframes in various timestamps
7. Open Build Profiles window and add macOS and Web Platforms
8. When added, switch to Web Platform
9. When switched to Web Platform, observe Animation window
Actual results: After switching Platform, Keyframes disappear in Animation window
Expected results: After switching Platform, Keyframes doesn’t disappear in Animation window
Reproducible with versions: 6000.5.0b5 (68fb1ff6adb3), 6000.5.0b8, 6000.6.0a5
Not reproducible with versions: 6000.4.7f1, 6000.5.0b4 (e1c9a1593d20)
Tested on (OS): macOS Silicon Tahoe 26.4.1