Question about extrusion width

[Budi67]

Hello

I have a question about extrusion width

I have a strange aspect on the verticality, it looks like over extrusion, but when we look the top solid layer it looks like under extrusion !!!!
At first, I was 0.90 for the extrusion multiplier, but my shells did not stick and my top solid layers was horrible, I am to manage at a good result with extrusion multiplier 0.93 and for the extrusion width I am manual 0.40

4 shells
7 top and bottom solid layers
Speed 40mm/s
Retraction distance 1.20mm
Retraction speed 35mm/s
Bondtech extruder directdrive

Have you an idea ?
A big thanks (sorry for my english)

[SWCNT]

More details would be helpful.
What material?
Is the 40 mm/s for the perimeter (shells) and the top/bottom layers?
Are you cooling? If so, what's the cooling setup? Single? Dual?
What printer are you using?
Why do you have 7 top and bottom layers? Why not have 2 and use 100% infill if you want a solid part?