Deleted tempo marking playing at the same tempo

This excerpt was taken from a full score that had a tempo marking of 78.

When bars were deleted, the tempo marking was deleted. I re-added the marking, but some instruments were then removed, which removed the tempo marking again. However, during playback in 1.3, it still sounds at the same tempo.

However, when playing 2.0, it sounds at the default.

I think 2.0 might be correct in what it's doing, but what should happen? I'm baring this in mind: #11603: Inputting empty Tempo Text name should list BPM

Using MuseScore 2.0 Nightly Build (f227ab7) - Mac 10.7.5.