diff --git a/docs/release-control/v6/internal/subsystems/monitoring.md b/docs/release-control/v6/internal/subsystems/monitoring.md
index c0ac04025a..5e249dedf6 100644
--- a/docs/release-control/v6/internal/subsystems/monitoring.md
+++ b/docs/release-control/v6/internal/subsystems/monitoring.md
@@ -1408,9 +1408,12 @@ for the tenant monitoring loop to exit before it refuses with
 `tenant_shutdown_incomplete` and keeps the data. Process shutdown and
 `RemoveTenant` keep the two-second `tenantMonitorShutdownTimeout`. Deletion
 gates the data on that wait, so the budget must cover a loop that is still
-starting up or finishing a tick: under CI load a just-used organization's loop
-took 8-10 seconds to see its cancelled context, and the two-second budget turned
-an ordinary delete into a refusal. A loop that never exits still refuses.
+starting up or finishing a tick. The observed case is mock mode:
+`Monitor.Start` runs `startMockMetricsSampler` synchronously before its select
+loop, and `prepareMockMetricsHistory` seeds seven days of fixture history
+without a context, so a just-used organization's loop took 8-10 seconds under CI
+load to see its cancelled context and the two-second budget turned an ordinary
+delete into a refusal. A loop that never exits still refuses.
 Proxmox physical-disk polling is also a continuity boundary. A failed or
 permission-denied `disks/list` call must remain an error so the monitor can use
 linked host-agent inventory or retain same-instance, same-node prior evidence;
diff --git a/internal/monitoring/monitor_additional_test.go b/internal/monitoring/monitor_additional_test.go
index eaaa70230a..bc771e5d42 100644
--- a/internal/monitoring/monitor_additional_test.go
+++ b/internal/monitoring/monitor_additional_test.go
@@ -1115,9 +1115,11 @@ func shortenTenantShutdownBudgets(t *testing.T, plain, deletion time.Duration) {
 }
 
 // A tenant monitor that is still starting up or finishing a tick can take
-// longer than the plain shutdown budget to see its cancelled context. In CI a
-// just-used organization's loop took 8-10s, so deletion refused with
-// tenant_shutdown_incomplete. Deletion waits on its own, longer budget instead.
+// longer than the plain shutdown budget to see its cancelled context. In CI's
+// mock mode, Start seeds mock metrics history synchronously before its select
+// loop, so a just-used organization's loop took 8-10s to stop and deletion
+// refused with tenant_shutdown_incomplete. Deletion waits on its own, longer
+// budget instead.
 func TestTenantDeletionWaitsForSlowMonitoringLoop(t *testing.T) {
 	shortenTenantShutdownBudgets(t, 50*time.Millisecond, 2*time.Second)