Influxdb with Telegraf

I uses telegraf DB in the influxdb for monitoring VCs with Grafana.

I uses those dashboards:

I noticed that some of my grafana dashboard return N/C in the dashboard even though the is correct. so when I checked why I noticed that some of the datastore for instance, have grater timestamp than the current timestamp. For example, datastore 2 return good values with lower timestamp that the DB has but the graph of datastore 3 return null cause he have grater datastore, and it’s return values with I do time <= now() + 3h instead of time <= now() - 3h.

Are all clocks in sync?

If yes, are all servers using the same time zone?

its the wired thing, its the same DB and the same VC and the same table, just sometimes I write in the query datastore = ‘xxxx1’ and sometimes datastore = ‘xxxx2’ and datastore ‘xxxx1’ works like magic unlike the second datastore

Someone know the answer?