No history data

My device send its data also to IOT in the BOX.
There was some development in this feature but now all is stopped.
can i delete this webhook ?
I prefer cayenne if the history data works.
When i select 3 or 6 months i see old data to 28 Febr. Then a gap to this day.
Can i delete Old data t clean up the graphic again? And how can i delete this old data???
Hope you can help me…

I would suggest creating a new device if you want to wipe history