Playback issues

When copying scores and parts from Sibelius, I noticed issues with playback. The sounds are octaves lower and also slower than the tempo written in the score.
When I tried to start a new score directly in Musescore I ran into the same issue. At first I managed to at least have the right pitch and tempo, for the guitar parts I am writing and hoping to playback correctly. But for some reason when I played it back the next day it gave me the same problem with lower (one octaves lower) and half tempo playback. In this example the pitch is correct, I re-used a regular clef instead of the 8bassa clef and transposed an ocatve up, but the tempo is not.