The string used for the translation is

"Synthesized tests using AutoTest%N(experimental)"

which I guess gets wrongly converted to a STRING_32 when being translated.

Am I doing something wrong by adding this character or there an issue in the locale formatter?

On my Ubuntu machine the printed text looks as as expected:

Synthesized tests using AutoTest
(experimental)

The reason for having a new line is that otherwise the wizard would become unnecessarily wide.