Scanned documents no longer searchable?

I used to use the OneDrive app on ios to scan business cards and save to OneDrive - They would get saved as PDF's which were then full text searchable, making it easy to find the information again.  I've tried it today and it no longer finds the text within the pdf's.

Anyone know if this has been turned off somewhere?  If so how do I turn it back on because it was really useful.