Additional input can be impossible after clicking an SButton in an Editor Window plugin

When a Level Sequence Player is created by clicking an SButton in an Editor Window plugin, any other buttons in the plugin window can no longer be interacted with until a click is made outside of the window.

Regression
No

1. Download the attached project.
2. Associate the project with your version of Main.
3. Open the ControlPlugin.uplugin file, and change "EnabledByDefault" to "true"
4. Build the project in Visual Studio.
5. Open the project in the Editor.
6. Click the ControlPlugin button in the Toolbar.
7. After the ControlPlugin window opens, start PIE.
8. In the ControlPlugin window, click the Create Player button (it should be the only enabled button).

RESULT:
The Create Player button is disabled and the other four buttons are enabled, but they cannot be interacted with.

EXPECTED:
The other four buttons can be interacted with (only the Delete Player button actually does anything).

WORKAROUND:
Clicking on the main Editor window and then back in the ControlPlugin window allows the enabled buttons to be interacted with. Note that clicking the Delete Player button results in the enabled buttons being disabled and the Create Player button being enabled, but it cannot be interacted with until the workaround is performed again.