I use OH 3.1 staple version (openhabian).
I will add from the GUI a new Item (Type: Number) and link this with a Channel.
The Item works fine and I get all data, but if I click on the Item value and check this on the graph then is here no data.
All other auto created persistence (create from Model > Create Points from Thing) works fine.
On the settings > persistence is RRD4J as default enabled.
I’ve delete the Item and create a new Item but the same behavior.