The last route taken is shown, not the route. It’s dynamic.
For battery powered devices: it can be in sleep mode. If zwave then wants to communicate with it, it says “unreachable”. Which is also the last status and not the status.
See also this post
• I’m sure one brand is just better or better compatible than others. I think trial-and-error is the way to go, swapping them for an other brand on an other floor maybe?
• Search on the net
• Or open a topic to request to people with flawless zwave networks or -devices, to show / describe their setup.
• Improve zwave mesh by adding router devices.
• Time how long a battery lives, schedule a reminder flow, and change it before the beep gets triggered 
• Battery measuring @ Homey is app dependent, and can be very off to unusable.
I think this might help:
• 1st thing I think is you should add a bunch of router devices (all 230V powered zwave devices). I count only 4 of them in your overview.
• Inform about others’ zwave setup.
• Make sure Homey is center based, so all device routes are possible with the limit of max. 4 hops
• If Coolcam or Greenwave are acting funny, replace them for something better? Or change all devices to Fibaro?
