@partial-block not working

[richardpickett]

Here's one of the files referenced, flex-columns.hbs:

<div class="flex-columns-at-1k flex-column">
  {{{@partial-block}}}
</div>

I use it like this:

{{#> "parts/flex-columns"}}
        <div>....</div>
        <div>....</div>
        <div>....</div>
{{/ "parts/flex-columns"}}

I see @partial-block was added years ago, I'm puzzled why it's not working now. Am I doing something wrong?

Although it's rejected by gscan, I can sftp upload the theme and restart my ghost and it works - including all these partial-blocks that are rejected by gscan.