Dear Alejandro,
Welcome to the forum.
We will be happy to help you and may need more information for confirmation.
Regarding "The onedrive ios app only shows libraries, the is no other button. The files app in ios content unavailable, the folder contents could not be displayed due to an unknown error.", could you upload some related screenshots for our confirmation?
Note: Remove nay private information before uploading the screenshots.
Does the issue occur suddenly? If yes, what did you do before the issue occurred?
If you go to the OneDrive for Business site (https://contoso-my.sharepoint.com/personal/username\_contoso\_onmicrosoft\_com), is the UI normal at your side?
Welcome to share any updates whenever you have time.
Your effort and time are greatly appreciated!
Sincerely
Cliff | Microsoft Community Moderator