Not bugs, just annoying!
Lyrics won't copy using the filter ... copying lyrics is a great time saver when writing choral works. This is annoying.
More annoying is that dynamic markings drop straight on top of lyrics, and very difficult to grab and move away with the mouse ... usually the lyrics gets grabbed instead.
Crescendo and diminuendo "arrows" cannot be copied and pasted, but can be dragged with Ctrl Shift so that isn't so annoying, I guess.
I am trying hard to stick with MuseScore over Sibelius, but these annoying things make it difficult.