I have migrated a Onprem Server 2010 to SharePoint Online for a customer. Everything went fine, i had to create new pages because this is a management system with visios on the pages. No problems there and they have som document library and one list.
After the migration i checked the rights and gave them new rights to the newly created pages. After a while we noticed that noone except the users with full rights can access any pages of the migrated site.
I have tried everything as I have come up with, I have escalated it to Microsoft with no luck.
Can someone pleas advice?
Things that have been tested:
Give users read, edit, with no luck, only when I apply full rights they can access the pages.
Request accesspermissions from users poit of view, accepted it from admin requests. Cleared cache, access the page from email and so on, nothing works.
Restored user groups.
Break inheritance, I hope I have done this on all pages, document librarys, lists and so on. Waited 12-24 hours before applying new rights
Break inheritance on masterpage, applied new rights, nothing works.
Removed all user groups except admin, what happens if I remove admins aswell, can I apply adminrights again or is the site lost?
Used Sharepoint designer to copy page to another site, doesnt work.
There are no sync between Active directory and M365.
The migration tool that has been used is Microsoft Sharepoint migration tool
I´m clueless, please advise me, really dont want to start everything over again!