Hard to say exactly without seeing your dyn in detail, but I think it’s due to the file centre of the rfa being some way from the geometry which would explain why when it is rotated it moves away from the original location:
Simplified example using a version of the rfa with the geometry moved (roughly) to the file origin
Roughly modified rfa attached: Crosslock_Secundair_MovedOrigin.rfa (604 KB)
Hope this helps,
Thomas