Workbook protect Fails?

[ErikJan]

Office 365 (b2002) on Win10/64

There's something odd with my Excel. If I open Excel (even in Safe mode) and in the Review-tab I choose "Protect Sheet" and click "OK", the button changes to "Unprotect Sheet". If I click that again (provided I didn't enter a PW earlier, which I didn't), the button changes back to "Protect Sheet". All as expected.

Now I do the same with "Protect Workbook" (the button just to the right of the "Protect Sheet"), I get the dialog and click OK (again, setting an empty PW). The button DOES NOT change this time and still shows "Protect Workbook". It behaves the same however as when I click it again, NOTHING happens. Clicking it a third time brings the PW dialog back again.

Seems as if the button text does not change. Is that my local installation? A bug in my build? Do others see this too?

(I stumbled onto this as I have VBA code that behaves very strange, I'm still debugging that)

[ErikJan]

Update: I just discovered that the text doesn't change but the button changes color (as if it's pressed down probably)...

MS moves in mysterious ways...

[HansV]

It has always been this way; I find the inconsistency irritating.

[ErikJan]

Confirmed in MS365 - b2011 and b2012