Hi kmelana,
I am sorry for the inconvenience caused. If there are any problems when using Office 365, we would like to help you to find the root cause and finally resolve it. Could you provide the following information for us so we can troubleshoot?
1. The subscription of Office 365 you are using.
2. I would like to confirm in which scenario the Office will let you sign in repeatedly: opening local files or opening files which are on the SharePoint Online. I will appreciate it if you can give more detailed description about this.
3. Could you provide screenshots with the error message for us? To upload screenshots, click Use rich Formatting in this thread and select Insert Image.
Thanks,
Elaine Hao