That's one of the oldest bugs in LilyPond. The work-around is to put
a grace with a spacer in the other staff too.
%%%
\version "2.22.0"
global= { \time 3/4 }
\score {
\new GrandStaff <<
\new Staff \relative { \global \acciaccatura b'8 c16 }
\new Staff \relative { \global \grace s8 r4}
>
Hello,
I stumbled on a weird display error when using \acciaccatura (or any
other grace note) on the beginning of a staff in a multi-staff environment.
Somehow, the time signature (and the key -- not shown in example) is
displayed before _and_ after the \acciaccatura.
Greetings
Martin
\ve
