Are you talking structural header? If so, AC has never done that. You have to insert a beam/etc yourself. (Or use the wall framing accessory... except that the ArchiCAD version uses the same size header for all windows, regardless of span. Don't know if the Cadimage one is smarter.)
If you're talking about the head frame and jamb extension which I don't see in your screenshot... the should both be present unless you turned them off or to zero thickness?
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AC 28 USA and earlier • macOS Sequoia 15.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB