I saw something similar with our HP M4345 after a firmware and Pharos upgrade to fix a different problem. I had to downgrade the Pharos software on the printer to resolve the logout problem.
We are having the same issue on our Canon Advance IR machines. Please post if you find a solution.
Pharos iMFP for Canon version 2.6.0 and later should resolve the logoff issue on iR Legacy MFPs reported by Carolyn. 2.6.1 is the current version available.
Pharos iMFP for Canon version 3.1.0 and later should resolve the logoff issue on iR-Advance MFPs reported by Jason. 3.1.0 is the current version available.
Both of these releases are available by contacting Pharos Support and opening a support ticket.