Alerting: resolved status email with firing image

Hi to all,
I configured alert rules on Grafana 9.0.2 end enabled grafana render plugin.
Alert rules based on time series panel work correctly and I receive email with correct image on firing and on resolved status.
If I create alert rule using only a query (influxdb v2) and I set Dashboard UID and Panel ID pointing to stat panel I receive the email with correct image on firing but on resolved status I receive the same image as firing state.
I store image locally on /var/lib/grafana/png.
I tried to remove the image created after firing alert but on resolved status no image was created and the email arrived with no image.

Can anyone help me?