Component repeat by symmetry has strange behaviour.

I want to repeat a simple part the other side of my assembly. It is the same part, just a different orientation by symmetry. The symmetry S1 has imposed a bizarre rotation that makes the symmetrised component not symmetric to the first one! Then I resymmetrised the two the other side S2. Once more, the symmetry isn't respected.

Any solution other than making the whole thing by hand?

Thank you.