Courtesy for Time Signature change is not saved (or loaded) correctly

Steps to reproduce:
1. Create score
2. Set time signature 1 to measure 1 and signature 2 to measure 2
3. Force line break after measure 1
4. select time signature in line 2 and disable "show courtesy" in inspector
=> sig changes disapears in line 1 (as expected)
5. save, close and reopen the score
6. sig changes re-apears in line 1 (bug)