Note that the issue might be SymfonyStyle::block() not properly handling inputs with a leading line break, but I'm fine merging this and revisit if the problem comes out again in the future.

@chalasr it's a bug with linebreaks at all on windows cli, not just leading. see the screenshot with a linebreak in the middle.

The code behind the screenshot:
$style->block(sprintf("Command \"%s\" is\nnot defined.", $name), null, 'error', " ", true);

Thank you @maxbeckers.

@chalasr, just a info because i figured out now ... using the constand PHP_EOL what is on windows \r\n will keep the block as expected:

So in future we should use the constant for linebreaks.

to me, we should rather make SymfonyStyle compatible with both PHP_EOL and \n in the input string.