Three slurs from a single voice to three voices?

[Kevin Cole]

Hi,

The hand-written score I'm looking at shows an F# with three slurs
coming off of it going to each of the three notes in the following
measure. I tried the following but it only shows one slur. What did I
miss?

%%%%%%%%
\version "2.22.1"
\language "english"

\new Staff {
  \relative c' {
    \time 4/4
    \key d \major
    d2 r4 fs4(            |
    <<
      \voiceOne {
        fs4)( g) g4 fs4   |
        fs4( b4) b2       |
      }
      \new Voice
      \voiceTwo {
        d,2) cs4 cs4      |
        d2 d2             |
      }
      \new Voice
      \voiceThree {
        b2) as4 as4       |
        b2 b2             |
      }
    >>
    \oneVoice
  }
}
%%%%%%%%

 (I also tried adding the starting F# to each of the three voices but
it made a two-headed F#. I didn't go so far as to add the F# to the
third voice, since it was messing up when I added it to the second,
and it seemed like there was probably a better solution than fighting
with the direction of the head for the single note, since it's one
more thing I don't know how to do, and seemed -- to me --
counter-intuitive as an approach.)