Still struggeling with MuseScore 3.0.1 (OS: Ubuntu 18.04.1 LTS, Arch.: x86_64, MuseScore version (64-bit): 3.0.1., revision: github-musescore-musescore-06a66a2)
This time it's to do with measure numbers. When inserting one 2/4-measure in a 4/4 piece, the numbers go wrong. In the status-bar at the bottom it reads that the bar after the 2/4 bar, has a starting count at the third count (sorry, I have a dutch install so all is in dutch, not familiair with all the lingo in English).
I'll try to attach some screendumps. Notice how the measure selected is changed, but the bottom status bar says otherwise.
EDIT. Screendumps here: http://molema.org/pictures/?dir=/Martin/MuseScore/01