PG connection gets lost

[Mike Rowan]

Morning all

I am in the process of testing a new Mac Mini running 10.14.6 as a "server"
to provide PostgreSQL 11.4 to my local network.  All works very well.

Except that some mornings, after it and a workstation have been left
running overnight (as usual) and Omnis Studio had a connection open last
evening, the connection is lost.  pgAdmin 4.21 had been left running.

Looking at the log I see:
WARNING:  terminating connection because of crash of another server process
DETAIL:  The postmaster has commanded this server process to roll back the
current transaction and exit, because another server process exited
abnormally and possibly corrupted shared memory.
HINT:  In a moment you should be able to reconnect to the database and
repeat your command.

I have not seen this on an earlier equipment, and wonder if there are any
clues as to what might be going on? pgAdmin4 the "other server process"
here?

I've put in an automatic recovery process, but would like to know what's
what.  Thanks for any  hints.