Unexpected system level log data

Firmware
1

I have a xenon with

SYSTEM_THREAD(ENABLED);

and

SerialLogHandler logHandler(LOG_LEVEL_WARN, // Logging level for non-application messages
{ 
    { "app", LOG_LEVEL_ALL } // Logging level for application messages
});

so I can track my application issues.

I keep seeing this though - what does it mean?

0001002933 [comm.protocol] ERROR: Event loop error 1
0001002933 [system] WARN: Communication loop error, closing cloud socket
got event 536964888 with value 64
got event 536964888 with value 64
got event 536964888 with value 64
0001003507 [comm.dtls] WARN: skipping hello message
got event 536964888 with value 64
2

I still get this unexplained message randomly - sometimes leading to a SoS 10 (panic)

got event 536964592 with value 64

Is this a local event - a cloud event ? I am at a loss as to where to search for it?

Any help welcome.