Interesting.
Yesterday (Tuesday 2pm Sydney time) the problem arose for me again. Gateway fails to reconnect to the IB Server when the IB Server restarts, forcing me to log in to Gateway again. My problem goes back a long way, is very intermittent, and I have an active ticket with IB on the matter.
Today, Gateway reconnected, but just looking at my logs now, I see similar messages to yours at time 14:05:23.663. Anyway, I didn't have to log in again today, the reconnection and login was automatic.
KH