Several users across three separate organizations were unexpectedly signed out of OneDrive and Outlook. The affected devices show the error "Microsoft.AAD.BrokerPlugin WebAccountProvider did not register with DCOM within the required timeout," along with AzureAdPrt: YES and WamDefaultSet: ERROR (0x80080300). We initially spent several hours troubleshooting without finding a fix, and then saw similar reports from four more users. Has anyone else encountered this issue, and are there known causes or reliable fixes?
3 Answers
Endpoint security software was another possibility, but the affected systems were using SentinelOne rather than Trend Micro. Removing SentinelOne temporarily did not resolve the issue, so it probably isn't the primary cause. Given that all affected machines are Lenovo Legion Go devices, I would investigate a recent Lenovo firmware or driver update next.
It may be worth checking whether the tenants use an identity provider where legacy authentication was recently disabled. Changes in federation or authentication policy can sometimes affect the Web Account Manager and broker plugin.
Check the TPM on each affected device and confirm that it is healthy, enabled, and accessible by Windows. A TPM or device-registration problem can interfere with the broker plugin and cached work-account tokens.

These tenants aren't federated with another identity provider, so that doesn't appear to be the cause. We also noticed that every affected device is a Lenovo Legion Go.