Incorrect application of slide master

I have a little Storyline puzzle: 

When I create a slide title placeholder in a master slide, it keeps the placeholder in place and the text aligned to the middle when the title becomes two or more lines. This is the desired state: 

When I use the layout on a slide, the text block appears to change to top alignment (although middle alignment is still selected), that is, multiple lines just go below the first line.

I need to keep the alignment in the middle, to work with the background (which I obviously left out here.) 

Any suggestions?