If this is happening with just one company, I would make sure I was using the browser they recommend and if I was, I would contact them about the issue. If it is happening with multiple companies I would try with different browsers and/or with a different computer altogether.
I have seen a problem similar to this once or twice over the years when it seemed to relate to my internet connection shutting down and when it came back I had timed out of the website so was returned to the login page.
I use Firefox for reports and make sure that I take the updates and upgrades on it so I have few problems. I recently had issues with a Win 10 update that spent more than an hour attempting to configure the system after making the updates. I used the restore function to go to a date about a month earlier when the system worked fine and as the updates came back in, things worked properly.