I’ve recently edited the membership of a large SCOM group containing Windows Servers that is populated both dynamically and explicitly, with sub groups as well. Despite it all looking OK in the SCOM console, it appears that some of the servers I removed are still in the group - I can see them on the Status Tile in advance view by selecting the group and class ‘computer’. Is there a way to force a recalculation of the group membership, or flush it somehow?
Have you tried remove-scomdisabledclassinstance ?
I use a very simple way to investigate issues like this. All you need is to figure out what are the discoveries that creates those instances. To figure out that… Open SCOM console right click on the relevant instance , select open powershell … it will open powershell command line with $context variable. Write $context.getscomdiscoveries()… in the result look for workflowid… copy it and write the command get-scomdiscovery -id past the workflowid… and the result is the responsible discovery for creating this unwanted instance now change the discovery and enjoy:)