Unified Search - finds "Frank" but not "Franke" ?

I have a PDF document that contains “FRANKE”

I search for “franke” - No matching Results.

The result does appear in the unified search panel when I just search for “frank” - but when I add the extra “e” it disappears.

I have confirmed the PDF does contain the text “Franke” in the text layer (I opened the PDF and searched for “Franke” and it was highlighted )

Can someone advise why unified search has not indexed “Franke” on my install.

[NC AIO Nextcloud Hub 8 (29.0.4) - on Docker / Linux Mint ]

[PDF is the Installation Manual 115.0250.638 001 from Kitchen Tap Sion Chrome - Brass ]

If you don’t see anything in the logs and more indicators, this might be a thing for the bugtracker (Issues · nextcloud/server · GitHub). Check out if there are no existing reports already.