No data points displayed by grafana while data is in the database


I am quite new to Grafana and I when I try to visualize some data, I have the error no data points. When I use my browser to the url http://:9200//_search?size=1000&pretty, the data is in the database but Grafana isn’t displaying it.

I checked the query with the query inspector and it appears that the answer is empty. How is that possible ? And is there any solution ?

I thought it could be due to time ranges because grafana uses epoch_millis while my timestamp is using the yyyy-MM-dd HH:mm:ss.ffffff format.

Thanks for helping me

my data is displayed by grafana with the correct datetime field but the next day. The day the data is sent to elasticsearch, grafana isn’t displaying it.
Can someone help me there ? Thanks