Razer Synapse not starting, sometimes, randomly

I do have the stuff working, sometimes, with my keyboard, mouse and Philips Hue working as expected. When it doesn't, I can quickly tell because my keyboard has the default light and key settings, so my profile is not loaded. It seems related to multiple users signing in under Windows. I do make sure to log every user out and restarting Windows. It sometimes helps. Doing the whole clean uninstall/reinstall seems to help for a bit too, but it doesn't take weeks before the problem resurfaces. Of course, it should work 100% of the time.

On Windows start the Razer splash screen starts, after that there is a Razer Central icon in the tray area. LMB click gives

• Log in to RAZER to get started!
  
• LAUNCH SYNAPSE
  

1. Gives me a window with 'Welcome Back' and my user name, so I guess I'm already logged in. Clicking my user name allows me to sign in again. After typing in my password and clicking LOG IN, I get a very unhelpful window with some boring details. LMB on the tray icon again just simple states 'Log in to RAZER to get started!' again. WTF is this UI design and UX...



2. LAUNCH SYNAPSE doesn't do anything. A quick wait pointer. That's it.

Right clicking the tray icon and clicking Razer Synapse does the same as 2.

Details:

Task Manager shows

and a GameManagerService (32bit).