Hi Joe,
Before moving on, I'd like to clarify the current situation:
1. Which Office 365 Plan do you use, P1 plan or E plan?
2. Does the issue affect all the users, or only some special users? If it is for a special user, please un-assign SharePoint Online license for the user, wait for about 20 minutes, and re-assign SharePoint Online license.
When a user is accessing SharePoint Online for the first time, it does need some time to prepare the user's profile for SharePoint Online. Please ensure you have assigned SharePoint Online license to the user, wait for a moment, and refresh the page to see if you can log in successfully.
In addition, could you provide more details about the issue or it'll appreciate if you capture a screenshot and post here.
Thanks,
Aaron Yuan
Before moving on, I'd like to clarify the current situation:
1. Which Office 365 Plan do you use, P1 plan or E plan?
2. Does the issue affect all the users, or only some special users? If it is for a special user, please un-assign SharePoint Online license for the user, wait for about 20 minutes, and re-assign SharePoint Online license.
When a user is accessing SharePoint Online for the first time, it does need some time to prepare the user's profile for SharePoint Online. Please ensure you have assigned SharePoint Online license to the user, wait for a moment, and refresh the page to see if you can log in successfully.
In addition, could you provide more details about the issue or it'll appreciate if you capture a screenshot and post here.
Thanks,
Aaron Yuan