Only one snippet is expanded

Hello,

I run an extension called Sliced Invoices in which you can set pre-filled text for certain fields.

This is what I have for one of them:

<p>Strictly 10 days from invoice date.</p><p>[AU_bank_details]<br>[EU_bank_details]<br>[US_bank_details]<br>[NZ_bank_details]</p><p>Your contact at Puzzle Factory: Dax Liniere – 0747 0747 750</p></div>

For some reason, only [NZ_bank_details] is expanded to the text saved in PostSnippets. It was originally listed first (NZ, EU, US, AU), but I thought that PostSnippets might only be expanding the first shortcode, but when I moved NZ to last place, it’s still the only one that gets expanded.

Under Manage Snippets, all 4 snippets I have saved have identical settings. I have triple-checked the snippet names are correct. Their order is AU, EU, US, NZ.
The content of the 4 snippets is basically the same, with only the bank details changed. None have unusual characters.

Any ideas what might be causing this and how we can fix it, please?

All the best,
Dax.