Lost caret and editor de-focused after pressing Enter

Scenario:
1)Type "abc.def"
2)Place your caret "abc.|def" with mouse and hit Enter. (After ".")
3)Caret is positioned at 2-nd line before "|def", which is as expected.
4)Hit Backspace, to merge again the 2 splitted lines. The result is "abc.|def"
5)Without doing anything else, hit Enter again.
6)The caret is lost and the text area lost it's focus.