Cannot clean some monitorings on a MSSQL server

Dear support,
the story is : I monitor a MSSQL server with X MSSQL instances using the MSSQL plugin. 2 MSSQL instances have been removed from this server. So I deleted the monitoring of these 2 instances,... BUT the servers is still raising alarm of "MSSQL - XXXXX service is down", even if these two monitoring have been removed.

I tried to use Remove DB entries tool and readd the device : Not OK,.. I tried to remove the windows services in Admin panel and readd it (as the monitoring is still used on another SQL server) : Not OK

I removed bothe MSSQL servers, do a Remove DB entries, delete windows services, readd the two devices and put back monitoring : same problemes.

My setup is : OpManager 11.2 x64 running on win2008R2, with embedded MySQL DB