Opening STEP files with assembly not saving with external references

Hello,

I upgrated to SW2020 SP1.0, and when I open an STEP file of an assembly and save it, I have only one assembly file, without parts.

In the assembly I have all the parts with references in the STEP model.

How can I save the assembly with all the parts in the same folder?

I check also the "Include all referenced components" but no results.

Thank you!

SolidworksImport/export