Courtesy time signature not displayed from 4/4 to cut time

MuseScore 0.9.6.3 (can't reproduce on trunk yet because of #7576: [Trunk] Crash on changing time signature)

1. Create a flute score in 4/4
2. Insert a system break
3. Drag and drop a cut time sign (C/) to the first measure of second system

Expected result : a cautionary time signature should appears at the end of the first line
Actual result : No cautionary timesig