Home Dashboard: Incorrect metric for 'DB uptime'

Hello

Home Dashborad -> click on db_uptime  "view" on one node -> explore shows

min by (node_name) (mysql_global_status_uptime{node_name=~"..."} or
mongodb_instance_uptime_seconds {node_name=~"..."} or
(time() - process_start_time_seconds{node_name=_"...",job="postgres_exporter.*"}))

On Postgres Servers the time the postgres_exporter is running is shown.
As I see this to be only minutes on all postgres Servers, and all the same amount of minutes
I think the restart of the pmm-server triggered a restart of the postgres-exporter. 
(Time of docker container matches those of postgres-exporters)

While restarting the exporters seems fine, show the time since start time of postgres-exporter as "db-uptime" is misleading. 

Regards