Dynamic placeholder content renders HTML as text string not mark-up

Select::make('venue_id')
->relationship('venue', 'name')
->columnSpan(2)
->live()
->required()

 Placeholder::make('venue_address')
//->content(new HtmlString('<p>Addr1<br />Addr2</p>')),  This works
->content(function (GET $get): string {
  $venueId = $get('venue_id');
  return ($venueId && $venue = Venue::find($venueId)) ? new HtmlString($venue->display_address) : '';
}), 

protected function displayAddress(): Attribute
    {
        return Attribute::make(
            get: function() {
                $addr = explode(PHP_EOL, $this->address);
                $fullAddr = array_merge($addr, [$this->town, $this->postcode]);
                return implode('<br />', array_filter($fullAddr));
            },
        );
    }