Sigh you seem to be expecting cailbre to preserve the layout of your text exactly. that's not going to happen. E-book are "reflowable" that means that they are "semantic" not layout oriented.
So a parapgraph in an e-book is represented as <paragraph>some text</paragraph>
Not a set of instructions like "leave 3 blank spaces then write the following characters, then change to next line". This is what a TXT file looks like to a computer.
calibre's conversion pipeline converts everything into a reflowable format internally, so you are never going to be able to preserve formats that specify exact layouts, like TXT and PDF.