Writer change case via Shift+F3 for all paragraph, not for selection

When I try to change case for individual words (highlighted) using Shift+F3, Writer change case for some other words in this paragraph. How can I change case only for highlighted text?
LO (x64)


If this casing has any specific significance for you, put it into a character style and apply this style instead of Shift+F3. It is much more reliable and customizable.

To Mike: thanks, I’ll try extension from Mihail Balabanov
To ajlittoz: thanks, but this solution is not convenient for my case, because I already use a character styles in this text for another purposes and different character styles will conflict

No problems with Shift+F3 for me. LO and (x86) on Windows 6.1.

Could be there something related to the .doc(x) format?

To LeroyG: just tried with .odt - the same problem. As Mike mentioned in his comment, this is a notorious bug tdf#49033