Describe the bug
The 'fffi' letter combination doesn't bahave according to Discretionary Ligatures function (or isn't defined in this alternate set). First letter 'f' is disjoined from the rest.

To Reproduce
Steps to reproduce the behavior:

1. Copy the following paragraph:
   Die Schifffirma plante neue Routen für das kommende Jahr. In den Büros wurden effiziente Pläne erstellt, um die Kunden zufrieden zu stellen. Gleichzeitig wurde die Sicherheit der Fracht geprüft.
2. Paste into https://rsms.me/inter/lab/

Expected behavior
It would be lovely to see the first 'f' joined the same way.

Screenshots

Environment

• OS: Sonoma 14.6.1
• App that renders the font: Safari in this case, but the lack of necessary ligature is applicable in all cases.
• Version of font: 4.#?

Additional context
Triple consonants are rather rare but occure in German compound words. Examples: Schifffirma, Schifffahrt, Sauerstoffflasche, Baletttanzerin, etc.