:p not quite
Think this through.
On a UI that is independent of lmms, you make a change in the ui scale.
Lmms scaled the container for this ui when lmms was opened
The new scale is complete unknown to lmms
Lmms therefore give the ui exactly the same container size, as before your scaled the un-related ui
That will be too small
Solution:
Restart lmms
Scaling perfect :p