Sentence case is not valid.

[storcke64]

Sentence case conversion does not work at all. Below is an example:

Properly functioning sentence case conversion should look like this :

If I enter some text and tell the software that it is sentence case, that should not be enough. The software must always validate that the RESULT is in fact always sentence case. The user cares about the result, not the input. Something like this is probably also affecting the other conversions.