Checking (Testing) if PWS Dashboard works proper

No High/Lows, where is history and graphs data used for, and ? cron ?

Your station data does not contain high-lows.
Two solutions:

  1. Modify the settings in the small blocks to not use the mont/year high-lows
  2. run a (free) cron-job every 5 minutes.

You can use a free cron-provider as explained in the links above.

Succes,
Wim