Zone login failing on first reboot following 11.3 agent inst

We are finding that after an upgrade to, or fresh install of, the ZCM 11.3 agent, on the first reboot user login to the zone fails. The ZENworks login box pops up, but all attempts to login fail. The second and subsequent reboots of the device correctly log straight into the zone with no prompts. This issue has only started with 11.3 - previous agent versions were fine. Anyone else seen this?