Unexpected result when entering augmentation dot with full measure rest selected

OS: Windows 10 (10.0), Arch.: x86_64, MuseScore version (64-bit): 3.6.1.515740707, revision: d0fc8e9

1. Create a new score: just a treble staff, 4/4, key of C, say.
2. Click on a full measure rest.
3. Press the keyboard . (period / full stop); or click on the augmentation dot in the toolbar.

Expected result: The duration dot highlights on the toolbar in anticipation of a duration command. But the full measure rest remains until the duration is received?
Actual result: The full measure rest changes to a (default) quarter note rest. The dot is ignored.