i downloaded the app in a lenovo idea tab, signed in and sync my library.
I tried to open the pdf associated with a paper that is available online, but in the little pdf icon what happens is: it goes from a question mark, to a brief 'processing cycle' icon, and then to a exclamation mark in red.
This happens to most of the articles, even when they are available online.
In the laptop app, the pdf that is 'automatically' attached when saving the paper to the library opens without problem.

Here is the debug ID D874105840

I hope the explanation makes sense
Thanks!