Thanks GarryP and Nermander. Using frames worked fine, although creating the lines by using tabs was a bit of a struggle. For some reason a tab would create the first line but after a carriage return a tab wouldn't do anything. I solved that by copying and pasting the first line.
When I tried I made a Paragraph style that contained the tab settings, and used that style for all the lines.
As opposed to many other programs, the "new" paragraph you get when hitting Enter does NOT inherit the direct formatting of the paragraph before. It usually gets the frames default style if I don't recall wrong.
There used to be similar issues when applying direct formatting during typing. If you typed a text, changed to Bold font and continued typing, the text you typed would not become bold... I'm not sure if that bas been fixed (because it's not what most users expect).
I think the issue is that Scribus applies the formatting only to the text selected, but when no text is selected the formatting does not "catch" anywhere.
I've learned to always use styles for everything...