Postgresql Crasching

Hi all,

We are experiencing the follow error in last few weeks:

Jan 25 16:03:51 FreeBSD11 kernel: pid 78639 (postgres), uid 770: exited on
signal 11 (core dumped)
Jan 25 16:03:51 FreeBSD11 postgres[73403]: [7-1] 2019-01-25 16:03:51.135 -02
[73403] WARNING: terminating connection because of crash of another server
process
Jan 25 16:03:51 FreeBSD11 postgres[73403]: [7-2] 2019-01-25 16:03:51.135 -02
[73403] DETAIL: The postmaster has commanded this server process to roll
back the current transacti
on and exit, because another server process exited abnormally and possibly
corrupted shared memory.
Jan 25 16:03:51 FreeBSD11 postgres[73403]: [7-3] 2019-01-25 16:03:51.135 -02
[73403] HINT: In a moment you should be able to reconnect to the database
and repeat your command.

This is our test machine and some days ago we try to increase memory and
vcpu, but the problem persist.

Some information:
root(at)FreeBSD11:~ # uname -a
FreeBSD FreeBSD11.2 11.2-RELEASE-p4 FreeBSD 11.2-RELEASE-p4 #0: Thu Sep 27
08:16:24 UTC 2018
root(at)amd64-builder(dot)daemonology(dot)net:/usr/obj/usr/src/sys/GENERIC amd64

root(at)FreeBSD11:~ # swapinfo -h
Device 1K-blocks Used Avail Capacity
/dev/da0s1b 4194268 0B 4.0G 0%

root(at)FreeBSD11:~ # df -h
Filesystem Size Used Avail Capacity Mounted on
/dev/da0s1a 141G 13G 117G 10% /
devfs 1.0K 1.0K 0B 100% /dev

# select version();
PostgreSQL 11.0 on amd64-portbld-freebsd11.2, compiled by FreeBSD clang
version 6.0.0 (tags/RELEASE_600/final 326565) (based on LLVM 6.0.0), 64-bit

Any suggestion?

Tks a lot

--
Att
Márcio A. Sepp