I spoke to a dev about this and they said (paraphrased)
**if you have the intl extension enabled for PHP (in your php.ini) and you use a language that has . instead of , then it will convert the numbers
Format::number passes your locale to the NumberFormatter::create() method (built-in php method) and this method returns the number. So Iād go to Format::number and var_dump($locale); at the top**
You can look at and edit \include\class.format.php and change this behavior.
