I am on the Mac and have 41.1.6 installed. Max sub.
In the Sermon builder if I type the following keytrokes:
Joel 2:25[Tab][Undo]
I am left with Joel 2:2 in my text. The 5 gets removed at the same time the undoing of the expansion of the verse reference.
Joel 2:25[CMD-ENTER][Undo]
does the same thing, left with Joel 2:2. The 5 is removed.
What I think is happening is the UNDO isn't really undoing the expansion of the text inline or block, but undoing the last character typed, which also removes the expansion.