I strongly recommend not to use "historic data graphs" in maps, it will put a heavy load on your PRTG server.
The data for the built-in graphs (2 hours, 48 hours, 30 days, 365 days) is permanently cached in memory for all sensors, thus creating the graphs is a matter of milliseconds.
Historic data graphs are always based on data from the "monitoring database", this means that for each bitmap rendering the monitoring data will be read from the disk and recalculated. On a map page this will happen every 60 seconds!
If you want a 24 hour graph please shorten the 48h graph to 24 hours (this is a setting in the admin control panel).
How can I add a graph to a map with a different time frame?