When underline style is already applied to a text, the style cannot be changed from the Font Properties dialog.

Workaround: Use the dropdown button in the ribbon.

Steps to reproduce:
- Select text.
- Open FontPropertiesDialog (or use ribbonButton for Undelinetext) and set underline style "Line".
- Submit the dialog.
- Right-click on the selected text again.
- Choose "Font..." from the context menu to open FontProperties dialog again.
- Change the underline style.
- Submit the dialog.
Expected: The selected underline style should be applied.
Actual: There is no applied underline style on the text.

Fix available in R3 2018 SP1 release.