Hi Sir,
>> all of a sudden, this two particular host doesnt show any vm at all. it is blank.
If we remove or "disconnect" VM in hyper-v host , it will tag "missing" state for that VM .
In addition , these VM and its state will be stored in SQL , you can find them in the following path (it is not recommended to edit VMM tables in SQL ):
SQL server management studio --> in object explorer click "data bases" and find VMM data base --> expand it and click "tables" --> find this table " dbo.tbl_WLC_Vobject" --> right click it and select "Edit top 200 Rows" , you will see these VMs .
Also, please use powershell command "get-scvirtualmachine" to check if these VMs exist .
If there is no record , I would suggest you to re-add the hosts into VMM again .
Best Regards,
El