PGAdmin4 - Not connected to the server or the connection to theserver has been closed.

When I select a table, right-click and select View/Edit Data > All
Rows (there are only 28 rows in this table) I get the following error
in PGAdmin4:

Not connected to the server or the connection to the server has been closed.

I've seen this happen in multiple different versions of PGAdmin4 but
am currently running 4.10. I've tried from several different
workstations and all exhibit the same problem. I am currently running:

Version
4.10
Copyright
Copyright (C) 2013 - 2019, The pgAdmin Development Team
Python Version
3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 21:26:53) [MSC v.1916 32 bit (Intel)]
Flask Version
1.0.2
Application Mode
Desktop

I'm connecting to a Postgres 11.2 server on CentOS:

PostgreSQL 11.2 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5
20150623 (Red Hat 4.8.5-36), 64-bit

Everything else in PGAdmin looks like it's loading fine; statistics,
DB listing, table listing, etc. I suspect that it might be something
with this particular table as I can view other tables just fine.
Here's the table schema:

CREATE TABLE public.entityconfig_section
(
    agency character varying(32) COLLATE pg_catalog."default" NOT NULL,
    id character varying(48) COLLATE pg_catalog."default" NOT NULL,
    entity_as_json json NOT NULL,
    last_update timestamp without time zone,
    CONSTRAINT section_agency_id_pri_key PRIMARY KEY (agency, id)
)
WITH (
    OIDS = FALSE
)
TABLESPACE pg_default;

Let me know if there's any additional information that's needed.

Thanks,
Dave