18:25 - Log-On Request, initiated from the aircraft terminal. This is the end of the link lost period that began at sometime between 17:07:48 and 18:03:41.
This is quite exactly 1 hour after the last SSR response.
I bet this is not coincidence and there is some technical explanation behind it.
Also: the 00:19 Log-on request was explained as a system restart after flame-out and subsequent RAT or battery kicks in or whatsoever. How then is the 18:25 Log-on request explained? There would have been no flame-out before that time. Generators failed? APU not started? Low altitude? There must be a technical reason for that, too.