Selecting measures / "all" does not copy clefs, text, various embellishments.
It appears that when multiple measures are selected (or when a single measure is selected) various embellishments such as clefs are not selected along with it. This makes copying and pasting complex passages difficult, and also makes deleting large sections problematic. Even worse, if you need to move a couple measures somewhere else, everything goes bonkers because certain items are left behind.
Comments
Which version of Musescore are you using? Which elements are not copied exactly? The current development version aa8bba3ced copies most of the elements (text, dynamic, clef etc...).
No info for more than a year. I close this issue. Most of the elements should be copied now (except Time signature). Create indvidual issue if necessary.