pgadmin4 - session timeout problem in browser

Hi all!

I use latest 3.5 version of *pgadmin4* as GKE docker service to working
with Google Cloud SQL (Postgres 9.6).
I always get random resetting browser session after connection to db and
get message that I need login again.

Tried to do workaround from this post:
https://superuser.com/a/729261

but after adding `.pg_service.conf` to /root directory (pgadmin4 is running
from root in container) I didn't see any changes with random logouts.
The problem seems same as after manually removing cookie from my browser.
Also I noticed that after random logout expires date of *pga4_session* cookie
is always changing to *1969-12-31T23:59:59.000Z *but before set to same
value as in config - 1 day.
I tried enable *debug* mode but it not gave me any answer: ```
2018-11-19 19:24:58,615: SQL pgadmin: Execute (dict) for server #1 -
DB:db_dev (Query-id: 1254648):
/*pga4dash*/
SELECT
(SELECT sum(blks_read) FROM pg_stat_database) AS "Reads",
(SELECT sum(blks_hit) FROM pg_stat_database) AS "Hits"
2018-11-19 19:24:58,937: INFO werkzeug: 10.4.0.1 - - [19/Nov/2018 19:24:58]
"GET /dashboard/ti_stats/1 HTTP/1.1" 200 -
2018-11-19 19:24:59,045: INFO werkzeug: 10.4.0.1 - - [19/Nov/2018 19:24:59]
"GET /dashboard/tps_stats/1 HTTP/1.1" 200 -
2018-11-19 19:24:59,045: INFO werkzeug: 10.4.0.1 - - [19/Nov/2018 19:24:59]
"GET /dashboard/to_stats/1 HTTP/1.1" 200 -
2018-11-19 19:24:59,153: INFO werkzeug: 10.4.0.1 - - [19/Nov/2018 19:24:59]
"GET /dashboard/bio_stats/1 HTTP/1.1" 200 -
2018-11-19 19:24:59,153: INFO werkzeug: 10.4.0.1 - - [19/Nov/2018 19:24:59]
"GET /dashboard/session_stats/1 HTTP/1.1" 200 -
2018-11-19 19:24:59,541: SQL pgadmin: Execute (dict) for server #1 -
DB:db_dev (Query-id: 830434):
/*pga4dash*/
SELECT
(SELECT count(*) FROM pg_stat_activity) AS "Total",
(SELECT count(*) FROM pg_stat_activity WHERE state = 'active') AS
"Active",
(SELECT count(*) FROM pg_stat_activity WHERE state = 'idle') AS "Idle"
2018-11-19 19:24:59,650: INFO werkzeug: 10.4.0.1 - - [19/Nov/2018 19:24:59]
"GET /dashboard/session_stats/1 HTTP/1.1" 200 -
2018-11-19 19:24:59,805: SQL pgadmin: Execute (dict) for server #1 -
DB:db_dev (Query-id: 6400046):
/*pga4dash*/
SELECT
(SELECT sum(tup_fetched) FROM pg_stat_database) AS "Fetched",
(SELECT sum(tup_returned) FROM pg_stat_database) AS "Returned"
2018-11-19 19:24:59,808: SQL pgadmin: Execute (dict) for server #1 -
DB:db_dev (Query-id: 9964067):
/*pga4dash*/
SELECT
(SELECT sum(blks_read) FROM pg_stat_database) AS "Reads",
(SELECT sum(blks_hit) FROM pg_stat_database) AS "Hits"
2018-11-19 19:24:59,809: INFO werkzeug: 10.156.0.6 - - [19/Nov/2018
19:24:59] "GET /dashboard/tps_stats/1 HTTP/1.1" 302 -
2018-11-19 19:24:59,839: INFO werkzeug: 10.156.0.6 - - [19/Nov/2018
19:24:59] "GET /dashboard/ti_stats/1 HTTP/1.1" 401 -
2018-11-19 19:25:00,035: INFO werkzeug: 10.156.0.6 - - [19/Nov/2018
19:25:00] "GET /dashboard/bio_stats/1 HTTP/1.1" 200 -
2018-11-19 19:25:00,036: INFO werkzeug: 10.156.0.6 - - [19/Nov/2018
19:25:00] "GET /dashboard/to_stats/1 HTTP/1.1" 200 -
2018-11-19 19:25:00,590: INFO werkzeug: 10.156.0.6 - - [19/Nov/2018
19:25:00] "GET /dashboard/session_stats/1 HTTP/1.1" 401 -
2018-11-19 19:25:00,596: INFO werkzeug: 10.156.0.6 - - [19/Nov/2018
19:25:00] "GET /dashboard/tps_stats/1 HTTP/1.1" 401 -
2018-11-19 19:25:00,601: INFO werkzeug: 10.156.0.6 - - [19/Nov/2018
19:25:00] "GET /dashboard/ti_stats/1 HTTP/1.1" 401 -
2018-11-19 19:25:00,607: INFO werkzeug: 10.156.0.6 - - [19/Nov/2018
19:25:00] "GET /dashboard/to_stats/1 HTTP/1.1" 401 -
2018-11-19 19:25:00,668: INFO werkzeug: 10.156.0.6 - - [19/Nov/2018
19:25:00] "GET /dashboard/bio_stats/1 HTTP/1.1" 401 -
2018-11-19 19:25:01,590: INFO werkzeug: 10.156.0.6 - - [19/Nov/2018
19:25:01] "GET /dashboard/session_stats/1 HTTP/1.1" 401 -
2018-11-19 19:25:01,597: INFO werkzeug: 10.156.0.6 - - [19/Nov/2018
19:25:01] "GET /dashboard/tps_stats/1 HTTP/1.1" 401 -
```
After some time it just stay without authorization as in log above.

Could anyone help me to find workaround, please?
Any suggestions in this situation?

Thank you in advance.