Node is monitored, is polling have snmp but its not charting availability

Hello friends, help me please. I made a massive load on the database of node of NPM. These nodes are Routers cisco 1811. now, i see the nodes for ups and downs, statistics on the interfaces, etcc.. but it doesnt show the availability chart (response time and availability) it saids "no Data for selected time period" but its showing the TODAY chart., like i said, the node its reporting alarms and events.

What i missed?