Sorry for the delay in response.
Would you try updating your app on an iOS device and check if that helps. Is the same file searchable on a desktop machine?
Will be waiting for your response.
The same PDF is text-searchable on my desktop, yes. I've found that only some of the text is searchable when copied to my phone. My Adobe Reader on iOS is updated.
Could you please let us know the dot version of Adobe Acrobat Reader and OS on your device.
Is it an issue with that particular PDF? Try to replicate the issue with other files.
Can you share that file to check it on our end?
If yes, please refer the steps provided here: How to share a document
We will be waiting for your response.