Timezone not work

I have installed the stack Prometheus and Grafana with Helm (prometheus-community/kube-prometheus-stack).
I set the timezone Grafana (Configuration > Preferences > Timezone : Europe/Paris (UTC+02:00) ).
But the graphs are always on UTC.
Any idea ?

There are a LOT of UTC-related threads on this forum. I would check them out. Tl dr is make sure your server running prom is also on utc