Site: add random delay before requesting meters (#19746)

core/site.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"math"
+	"math/rand/v2"
 	"strings"
 	"sync"
 	"testing"
@@ -481,6 +482,9 @@ func (site *Site) collectMeters(key string, meters []config.Device[api.Meter]) [
 	mm := make([]measurement, len(meters))
 
 	fun := func(i int, dev config.Device[api.Meter]) {
+		// decouple potential double-connects on modbus
+		time.Sleep(time.Duration(rand.Uint64N(uint64(100 * time.Millisecond))))
+
 		meter := dev.Instance()
 
 		// power