This paragraph has got a common paragraph style, where the right margin and only the right margin is set to 2.5cm. The list and not the paragraph style references the numbering style. The numbering style has a label position at 3cm and an indent and tab stop at 4cm.
Notice, that the right margin is lost, but the label position is correct and the referenced list style is used.
This paragraph has got an automatic paragraph style for direct formatting. It references the style where the right margin is set to 2.5cm. The numbering style is set on the automatic style and the left margin and the first-line indent are set to 0cm there. The numbering style has a label position at 3cm and an indent and tab stop at 4cm. The list does not reference the numbering style.
The explicitly set 0cm forces the paragraph to the paragraph indents, ignoring the numbering indents. That is correct! But the list style from the paragraph is not used; LO uses a default.
This paragraph has got a common paragraph style, where the right margin and only the right margin is set to 2.5cm and the above mentioned numbering style is referenced by this paragraph style. The list does not reference the numbering style.
Notice, that the label position of the list is used. But it is the default list and not the referenced one. In addition the right margin from the paragraph style is missing.