Impacted versions:[Odoo13] psycopg2.extensions.TransactionRollbackError

Steps to reproduce:
load website module, enable on the frontend two languages on a clean db.
switch to another language.
ubuntu 18.04, postgresql 10.10

clean deployment on lxc container with ubuntu 18.04.
using setup https://github.com/Yenthe666/InstallScript
started with a clean demo database


Current behavior:
(Odoo-server.log)

Traceback (most recent call last):
File "/opt/odoo13/odoo13-venv/lib/python3.6/site-packages/werkzeug/serving.py", line 270, in run_wsgi
execute(self.server.app)
File "/opt/odoo13/odoo13-venv/lib/python3.6/site-packages/werkzeug/serving.py", line 258, in execute
application_iter = app(environ, start_response)
File "/opt/odoo13/odoo/service/server.py", line 414, in app
return self.app(e, s)
File "/opt/odoo13/odoo/service/wsgi_server.py", line 140, in application
return ProxyFix(application_unproxied)(environ, start_response)
File "/opt/odoo13/odoo13-venv/lib/python3.6/site-packages/werkzeug/contrib/fixers.py", line 152, in call
return self.app(environ, start_response)
File "/opt/odoo13/odoo/service/wsgi_server.py", line 117, in application_unproxied
result = odoo.http.root(environ, start_response)
File "/opt/odoo13/odoo/http.py", line 1281, in call
return self.dispatch(environ, start_response)
File "/opt/odoo13/odoo/http.py", line 1251, in call
return self.app(environ, start_wrapped)
File "/opt/odoo13/odoo13-venv/lib/python3.6/site-packages/werkzeug/wsgi.py", line 766, in call
return self.app(environ, start_response)
File "/opt/odoo13/odoo/http.py", line 1454, in dispatch
response = self.get_response(httprequest, result, explicit_session)
File "/opt/odoo13/odoo/http.py", line 280, in exit
self._cr.commit()
File "/opt/odoo13/odoo/sql_db.py", line 163, in wrapper
return f(self, *args, **kwargs)
File "/opt/odoo13/odoo/sql_db.py", line 388, in commit
flush_env(self)
File "/opt/odoo13/odoo/sql_db.py", line 67, in flush_env
env['base'].flush()
File "/opt/odoo13/odoo/models.py", line 5215, in flush
process(self.env[model_name], id_vals)
File "/opt/odoo13/odoo/models.py", line 5206, in process
recs._write(vals)
File "/opt/odoo13/odoo/models.py", line 3522, in _write
cr.execute(query, params + [sub_ids])
File "/opt/odoo13/odoo/sql_db.py", line 163, in wrapper
return f(self, *args, **kwargs)
File "/opt/odoo13/odoo/sql_db.py", line 240, in execute
res = self._obj.execute(query, params)
psycopg2.extensions.TransactionRollbackError: could not serialize access due to concurrent update - - -

(postgresql-10-main.log)

2019-10-08 14:23:24.775 CEST [28786] odoo@demo ERROR: could not serialize access due to concurrent update
2019-10-08 14:23:24.775 CEST [28786] odoo@demo STATEMENT: UPDATE "website_visitor" SET "write_uid"=2,"lang_id"=17,"write_date"=(now() at time zone 'UTC') W$

Expected behavior:
select (edit / view) the other language (either in logged in user or guest)