Hi,We have a simple setup - a single ADFS server running on Server 2012 authenticating users to Office 365. We are not using ADFS proxies, but traffic does pass through a reverse proxy.
When a userA logs in, they sometimes get logged in as userB - if they change a document in SharePoint, it shows as userB and they receive userB permissions. Logging off/on to Office365 solves the problem (they login successfully as userA)
There is no pattern about which user gets logged in as which user. I have a suspicion it may be because two users login at the same time, but I can't prove this and we can't reproduce it on demand.
Generally the user doesn't notice immediately after login so it's hard to search in eventvwr on the ADFS server.
What is the likely cause and how should I troubleshoot this? Enable debug logging on the ADFS server? Clearly this is a pretty serious problem.
Any help appreciated.