After all these years, it still is frustrating that Cubase doesn’t handle 12/8 correctly. Per wikipedia:
In compound meter, subdivisions of the main beat (the upper number) split into three, not two, equal parts, so that a dotted note (half again longer than a regular note) becomes the beat unit. Compound time signatures are named as if they were simple time signatures, in which the one-third part of the beat unit is the beat, so the top number is commonly 6, 9 or 12 (multiples of 3). The lower number is most commonly an 8 (an eighth-note): as in 9/8 or 12/8.
Please, Cubase, finally give those of us that use compound meter a grid that actually respects normal musical convention and for the love of God, FIX THE BPM so that BPM is determined by a DOTTED quarter note in 12/8 and not a quarter note!