What/Why:
function_orchestrator_router_request_duration_seconds cannot be queried on Grafana because it doesn't seem to get initialized as it should in the wrapRouteHandlers function. So I can't do this:

sum(rate(function_orchestrator_router_request_duration_seconds_sum{site="$site", prometheus="$prometheus"}[5m])) / sum(rate(function_orchestrator_router_request_duration_seconds_count{site="$site", prometheus="$prometheus"}[5m]))

How:
figure out why and fix it?!