The system is interpreting <v> as an HTML tag, and therefore it's not shown. Not all HTML tags are supported, but e.g. <b>, to make things bold, works:
Notice that the tags seem to have gone here as well, but in this case they do have an effect. For a list of supported tags, see What HTML tags are allowed on ...
As mentioned in the Editing Help, you can use two spaces after each line:
> This is one line
> This is the next line
> This line contains *italics* and **bold**
This is one line
This is the next line
This line contains italics and bold
Alternatively, you can put an HTML line break (<br/>) after each line, but that's more ...