Zéro width spacer are not correctly saved

When making the layout of the parts, I want to have some spacers set to 0 width one some parts and non zero width on other parts.
I do this, e.g., before a one measure coda. On some parts, I want to have to coda measure on the same line has the preceding measures but separated by a space. I use a spacer with a non zero width. On some part, I want that coda measure on a new line, and therefore I set the spacer's width to 0.

In the example score, I have use 2 horizontal spacers.

In annex both the exports of the score when I saved the score. With some spacers set to 0 width.
And the .mscx file. When one opens it, the spacer with a 0 width have again a non zero width.