One of my feeders has a similar problem, after about 20 hours fr24feed loses connection to the network. All other services runs fine.

I have tried the gai.conf ipV6 fix to see if that helps.

2018-09-04 12:03:42 | [time][i]Synchronizing time via NTP
2018-09-04 12:03:42 | [time][e]Failed to synchronize time
2018-09-04 12:03:44 | [feed][i]Downloading configuration
2018-09-04 12:03:44 | [e]Socket is not valid, errno: 24
2018-09-04 12:03:44 | ERROR
2018-09-04 12:03:44 | [e]Could not retrieve configuration from Flightradar24
2018-09-04 12:03:44 | [feed][i]Failed, Sleeping 30 seconds
2018-09-04 12:03:44 | [time][i]Synchronizing time via NTP


/M