Edit similar text lines by removing a line return leads to an unexpected result

Nightly24f420b / Windows 7

The main point of this issue has been solved: #60931: Deleting multiline text in frames cause crash

But it remains a related and mentionned point in this previous issue.

So:

1) Open this file: test file.mscz

2) Duplicate in the second measure (select the whole rest -> Ctrl + T etc.) the content of the first measure staff text.
So: with a gap (enter key) between the first and the second text line. Four text lines are necessary (no issue with three)

3) When you have finished to type the fourth line, stay in Edit mode (highlighted). It's a necessary condition.

4) With arrow keys, place the cursor before the second text line (before the T) -> BackSpace

Result: as expected

5) Repeat in the third measure, the same previous steps. But when you have finished to type the fourth line, EXIT the edit mode (by clicking outside the frame, or double Escape)

6) Now, last step, double click on the text to Return in Edit mode -> Place the cursor before the same second text line -> BackSpace

Result: inexpected.

Same result of course with text in frames.

- Note that if the text line is different (see example in the first measure of the second system), there is no issue.