WebUI doesn't show graph by locations

when I want to see devices filtered by locations choosing “DEVICES/GEO Locations/Specific location”
libre listed me list of devices, but when i want to click on any graphs on the list it shows me nothing:
ex. librenms/devices/ location=21 /format=graph_ping_perf/from=-24hour/to=now/
its strange because when i choose specific type of devices every graphs works fine
ex. librenms/devices/ type=firewall /format=graph_ping_perf/from=-24hour/to=now/

best regards

I have also this problem with my LibreNMS personal installation at home (6 devices monitored via SNMP). I have 3 “logical” locations for my devices, no real location with longitude/latitude.

When I choose devices filtered by location, the list of devices is correctly displayed http://librenms.xxx.xxx/devices/location=4 but when I select a type of graph, no graph are displayed http://librenms.xxx.xxx/devices/location=4/format=graph_processor/from=-24hour/to=now/

Everything works perfectly with devices filtered by type (Server/Firewall/Storage for my personal install).

If needed, I can do some tests/debug/coding to analyze/fix this issue (competent with PHP/Python/SQL stuff).