Regression - Animation have no button "Add Property" when the object is selected

2) How can we reproduce it using the example you attached
1 Create new project
2 Open somewhere Animation Window - tab, and make it not visible by opening some other tab
3 Close the project without saving
4 Open project again
5 Create Cube in Hierarchy and select it
6 Make visible the Animation Window - tab
Actual result: the Animation Window - tab have no button "Add Property"

Please see attached video