Key signatures: naturals never displayed on key change

Steps:

1. create a score with three empty measures
2. apply Emaj (4 sharps) to bar 1
3. apply Cmaj (no sharps/flats) to bar 2
4. apply Abmaj (4 flats) to bar 3
5. add D quarter notes to each bar
6. play the score

RESULTS:
The score plays correctly (D#, D, Db) but it is displayed incorrectly. See screenshot.

Attached score created as a result of the steps above.

WORKAROUND (kinda) :
I do notice that re-applying the empty key sig to bar 2 will get it to show up. However, on longer, non-test scores, I'm seeing the key signatures come and go - I can't seem to get them to stick.