Session Timeout - Query Tool hangs indefinitely due to login required

Hi,
I get logged out from time to time which leads to my current query and all ui state being lost.

If I happen to try a query I just get a spinner and 'Initializing the query execution!' that hangs forever, 
if I navigate I get a blue popup with: 'Please log in to access this page.'.

In the console I see that my requests get redirected to
http://localhost:81/login?next=%2Fdashboard%2Fsession_stats%2F1%2F16384
and as a result I get a
 Uncaught SyntaxError: Unexpected token < in JSON at position 0 at JSON.parse (<anonymous>)

There seems to be quite a short session timeout and/or no working keepalive (if I put my browser tab into the background)

pgAdmin 4
Version: 2.0
Python Version: 2.7.5 (default, Aug 4 2017, 00:39:18) [GCC 4.8.5 20150623 (Red Hat 4.8.5-16)]
Flask Version: 0.11.1
Application Mode: Server (run in docker)
Browser: Chrome Version 62.0.3202.62 (Official Build) (64-bit) on Ubuntu