OCR functionality on iOS

Operating system

iOS

Joplin version

12.14.6 (iOS)

Desktop version info

2.14.20

Sync target

WebDAV

Editor

Markdown Editor

What issue do you have?

OCR search function works great between the Windows plattform and WebDAV. Search results on PDFs and JPGs matches perfectly.
However when I search on a iOS 17.3.1 (IPhone+IPad) there is no search match available. Even when I'm searching the same keywords.
Is there a specifc setup procedure for iOS required? I have not found anything so far on the Joplin support site.