@dusan.naus.trz - I'm not a drawings expert at all, but the way Fusion handles mirrored components, this is exactly what I would expect. A mirrored component is a different component (it is a mirror, not a rotation). If you want rotated components, use a circular component pattern, not a mirrored component. Those will show up as instances of the same component, and will be combined in the parts list.
Yes, I use the rotation. But this is not a complete solution. In Inventor, you can specify whether to mirror components as new or to keep existing and to mirror when mirroring. If I missed 1 screw on the right side, when using rotation it would be missing on the opposite side. I put it on top. The solution for the future is up to you programmers.
I agree with the original poster. A rotation is not a solution. I need to do the same thing, mirror across a plane, but make a copy of the component so it shows up correctly in the BOM.
Same situation here, though a much lighter version of it.
The only workaround I could find was circular pattern.
As my element is not symmetric, I had to perform a couple of joint operations to re-align all parts.
Though it should be much easier if the mirror operation left you with some choice.
Best,