Trim and order of surfaces to trim

Hi,

Why can't I get a trim made up of the 4 internal parts of the bunch entered into the trim noyau1 ?

OK, i make an error with the extrude3, bottom part.

So i delete it, enter the extrude3 left part in 3rd, offset10 in 4th.

Then, why Offset10 isn't trimed in its rear part ?

More funny : if I invert again extrude3 and offet10, offset10 being in 3rd position (so the 4 surfaces are entered in clockwise), then i can get the trim i want, except with offest4.

If surfaces are entered in clockwise, offset4 in last position (so I delete offset4, to enter it again) , then I get the result i want.

What happens with this file ?

Tx for your lighting.

SolidworksSurfacing