Unable to delete a material from a BOM

Hello All,

I am trying to change the unit of measure of a material, but I get an error that it is assigned to a BOM

so, I went to CS02 and I deleted it, but when I go to Cs03, I still see it, hence I am unable to change the UOM.

I don't see anything in CS02 now, so why do I still see the entry in CS03? How can I delete it and change the unit of measure on the material?

Please help me