Hub went to getting start page after error 500

Ok. When you did the Soft Reset process:

Unsure what you mean that “everything was fine until now”.

Does this mean that the Z-Wave Radio did work for awhile, and then stopped working?

Is it possible that your hub is overheating? Sounds like you may be having a Z-Wave Radio hardware failure.

May I suggest you install @thebearmay’s Hub Info driver and look at the hub temperature?

Give it about 5 minutes to stabilize. Data returned by hub to driver isn’t good for first few minutes.