Based on the output of free, I’m inclined to think that you were legitimately low on memory…
can you try running free -h and then immediately running ghost restart to see if ghost complains about memory?
If free + buff/cache >= ~150MB Ghost should not complain, but there are times where the buff/cache is not accounted in the lib.
ghost run should only be used for debugging since there is nothing to restart the Ghost process is if it crashes, and it won’t be running under the correct conditions.