Steps to reproduce:

1. Create Zabbix trapper item with Data type Numeric (unsigned);
2. Send one value using zabbix_sender;
3. Navigate to Monitoring→Latest data;
4. Click on Graph.

Result:
Horizontal green line fills all time interval of the graph.

Expected:
As far as I recall graphs for trapper items always had a horizontal line from the latest value in the interval to the right Y axis, data has never been extrapolated to the past.

By the way, Values and 50 latest value correctly show a single value.