Sharepoint is slow and got trouble when multiple users editing the same document + OneDrive issues

Hi

We are experiencing a slow Sharepoint Online environment and often have to reload the pages to get all content of a page.

We have issues when we are multiple users editing the same word-document. The versions don't get synced and we often have to restore older versions and redo the work. Most of the users are using Word's desktop app as the webbversion differ in layout and font from the desktop app document.

We also have a reacurrence of onedrive's that fails to sync. Pausing and resume the sync doesn't work so we have to do a reset of OneDrive from time to time.

Any clues on whats the issue causing this?