A group of Microsoft Products and technologies used for sharing and managing content, knowledge, and applications.
Dear Angelos Dragoti,
Good day! Thank you for posting to Microsoft Community. We are happy to help you.
As per your description, it seems that you are having issue with SharePoint Android app.
If the understanding above is right, please navigate to Settings in the device > SharePoint to check if network connection is enabled for the app.
Meanwhile, please uninstall SharePoint app, restart the device and reinstall SharePoint back to check the outcome. We'd also recommend you change to another network connection to see if there could be any improvement.
If the issue still persists, considering that there could be limited troubleshooting steps user can do for SharePoint mobile app, more resources need to be involved in to help you further. In this situation, we sincerely recommend you contact your Microsoft 365 administrator, follow steps in this article to create a support ticket with Online Support. The support team over there has higher permission than us, they can remotely help check the situation on your side, involve more resource to collect logs and help you do troubleshoot. This would be a more efficient way in handling this case for you.
For reference: How do I find my Microsoft 365 admin?
Sorry for the inconvenience again. Your patience and understanding are highly appreciated. Hope you stay safe and healthy.
Sincerely,
Rhoda | Microsoft Community Moderator