Octave line bug for acciaccaturas?

I might be wrong, but I may have discovered a bug…

I’ve a low-register acciaccatura at the start of an otherwise empty bar. If I try to apply an ‘8vb’ sign to this, no 8vb sign appears. - Is this because Dorico thinks that the acciaccatura does not have any duration?

To move a clef either after a run of grace notes, choose Edit > Notations > Clef > After Grace Notes.

However, I find I can happily create an octave line with a selected grace note. Octave lines can both start and end at grace note positions if need be.