The formatting would seem to depend on a number of factors.

The forum software is fairly old and doesn't like some of the modern browser programs.

On my phone I have to use 'mobile view' to read or post a on a thread. But I have to switch from that to standard view to remove any spam or see any of the 'mod' options.
But I can't post in standard view mode as it just inserts about 100 carriage retuns into any text.

So, yeah depending on what software platform and browser you are using - it will remove carriage returns.

Firefox on windows works fine.
So I would always recommend firefox if you can use it. Think there's a mac version as well.
Although it doesn't, make any difference on android 10.