We just ran into this on a new computer. Ignition was installed and started up on a Windows 10 computer set to the wrong timezone (one hour earlier) and then the timezone was set correctly in Windows. Ignition gateway status page showed the correct time for the new timezone. But Designer–and Vision clients set to use gateway timezone–were showing the correct gateway timezone, but the wrong time. Restarting Ignition gateway did not help. Neither did restarting Windows on the computer running the gateway.
Closing and re-opening Designer and Vision Clients resolved the issue. The previous steps (gateway and Windows restarts) may or may not have been necessary.