dragging breath marks makes the score/measure extend and lag issues

Currently running musescore 3.0.1 on a Dell Inspiron laptop (I despise it) and Windows 10.

I just downloaded musescore 3.0.1 (was still using some version of musescore 2 until this morning) and was making some edits to a piece. I went to drag a breath mark (knowing it wouldn't (or shouldn't) do anything) and it caused the score/measure to extend to a ridiculous length the more I tried to move it. Pressing ctrl+z did not fix the issue and did not replace the breath mark to its original position.

Musescore 3 is also laggier now than it ever was before (never had lag issues with musescore 2). This lag made it impossible for me to attempt to recenter the breath mark mentioned above. (I'm also having issues with lag while moving notes with the arrow keys, typing text/backspacing text, etc.)