I have a similar issue. Server had a single player on it, not sure exactly what they were doing at the time. I have also observed this behavior from time to time. Once the "crash" has occurred, the server will keep sending crash reports, approximately every 75 minutes (in bursts of a couple dozen.) Sample logs from below (I can try turning on tracing to help track down the issue?)
02:55:47
Avorion server Beta 0.28.1 r18395 5f179a296d34 running on Amazon Linux 2 starting up in "/data/avorion/galaxies/Galaxy"
02:55:47
CPU: Intel(R) Xeon(R) Platinum 8275CL CPU @ 3.00GHz 2 Cores
02:55:47
RAM: 3GB
06:20:16
saving sector (-110:-210)
06:20:16
sector (-110:-210) saved to "/data/avorion/galaxies/Galaxy/sectors/-110_-210"
07:30:24
scheduled save for sector (-117:-206), 0x7f22b5d94530, entities: 0
07:30:24
saving sector (-117:-206)
07:30:24
sector (-117:-206) saved to "/data/avorion/galaxies/Galaxy/sectors/-117_-206"
07:30:24
scheduled save for sector (-152:-178), 0x7f22c59a5ae0, entities: 520
07:30:24
saving sector (-152:-178)
07:30:24
sector (-152:-178) saved to "/data/avorion/galaxies/Galaxy/sectors/-152_-178"
07:30:24
scheduled save for sector (-142:-189), 0x7f22ce7109f0, entities: 0
07:30:24
saving sector (-142:-189)
07:30:24
sector (-142:-189) saved to "/data/avorion/galaxies/Galaxy/sectors/-142_-189"
07:30:24
scheduled save for sector (-130:-198), 0x7f22bc725b80, entities: 0
07:30:24
saving sector (-130:-198)
07:30:24
sector (-130:-198) saved to "/data/avorion/galaxies/Galaxy/sectors/-130_-198"
07:30:24
scheduled save for sector (-117:-206), 0x7f22b5d94530, entities: 0
07:30:24
saving sector (-117:-206)
07:30:24
sector (-117:-206) saved to "/data/avorion/galaxies/Galaxy/sectors/-117_-206"
07:30:24
Triggered saving of all server data.
07:30:24
scheduled save for sector (-110:-210), 0x7f22bc3f22a0, entities: 2035
07:30:24
saving sector (-110:-210)
07:30:24
sector (-110:-210) saved to "/data/avorion/galaxies/Galaxy/sectors/-110_-210"
07:30:24
Hang of at least 30 seconds detected, sending stack traceSending crash report ...
07:30:24
Crash report sent successfully!
07:30:24
Hang of at least 30 seconds detected, sending stack traceSending crash report ...
07:30:24
Crash report sent successfully!
07:30:24
Hang of at least 30 seconds detected, sending stack traceSending crash report ...
07:30:24
Crash report sent successfully!