I have noticed recently that when i open assemblies, sketches used to create features in the parts are being shown. I will right click the sketches and hide them but when I open the assembly again they are all showing.

I know i can hide all, but thats not what I want to do as i regularly use sketches from features for referencing to other features, I just want the sketches I dont need to hide and stay hidden.

Ive never had this issue before, I have not updated solidworks in a while (currently using 2018 SP01), not sure if I have changed a setting inadvertently thats causing this, but its starting to get annoying constantly hiding sketches each time I open an assembly.

Screenshot attached.