Canvas apps use different punctuation for formulas depending on the locale of the author.
In the US, a formula might look like this:
And in Spain that same formula looks like this:
This makes sense for novice users who don't normally write code and follows the Excel model. For a novice that has been writing 12,59 all their life it makes no sense to force them to write 12.59 for PowerApps. You can read more about hsi behavior in Build global support into canvas apps.
But professional developers are accustomed to using a dot for a decimal separator and a comma for argument lists to functions. All modern programming languages force this syntax. It is possible to change the language of the browser to a language and region that uses the dot decimal separator, but that requires that all of the PowerApps Studio changes to that language and region.
Should PowerApps provide a setting so that authors can select the declimal separator they use, independent of the language/region setting?