truncate issue , possibly

hello, we have a 9.5.16 instance ( upgrade is in plan) and we hit a strange
issue yesterday and i haven't found any cause as yet.

a user ran a truncate cmd from pgadmin3 ( upgrade is in plan as well) on a
2M row table
in that session, the user received the following msg

FATAL: terminating connection due to Administrator command.

in the log we found the following

2022-07-13 09:30:03 BST [3317-1] webapps(at)prod01 FATAL: terminating
connection due to administrator command
2022-07-13 09:30:03 BST [3317-2] webapps(at)prod01 STATEMENT:

truncate table latest_forecast_log

2022-07-13 09:30:03 BST [5644-1] postgres(at)prod01 WARNING: PID 3317 is not
a PostgreSQL server process

a truncate test with pgadmin4 on a copy of the table in another 9.5
instance worked as expected.

I then tested pgadmin3 against another 9.5 instance and that worked as
expected.

we dumped the data to a cvs and i will run the truncate from psql at the
server but before i do that i'm curious if anybody has some insight on the
error above.

thanks very much