I'm using Adobe Acrobat XI to prepare pdf files since years. However, with large text - e.g. converted ebooks - I result in PDF files, which on deskop reader work fine: e.g. allow text highlighting. But on Android mobile i cannot mark text and for that I'm not able to highlight text or underline - however, adding text and notes is possible. I refer to PDF files uploaded to Adobe cloud.
Even extracting a few pages of such a file doesn't help no marking of text possible. The size should not be the problem.
On desktop text can get copied. Security setting should be a problem.
Interestingly, highlights done on desktop reader do appear on Android mobile reader, can even get there deleted and text stored back to cloud.
I hope that it is possible to save in Adobe Acrobat XI files in a special format/setting. Maybe the automatic WEB optimization inhibits some features in order to reduce file size. Unfortunatelly, up to now I haven't found an appropriate option.
May be someone on the forum can help
Could you please let us know the dot version of Adobe application and OS you are using on your device.
If possible, please share one such file with us, so we can check it on our end.
I have sent you a private message with email address to send the file.