As Michael said, if you want to flow without this problems you have to reconstruct this part with a loft or sweep method.

My proposition, but I'm not sure this is the more orthodoxe one, is to follow this process :
- drawing some horizontal lines (use array or do it one by one)
- project these lines on you object
- select the object
- (Construct / Curve / Project)
- select the lines
- with the curves you did plus the top and bottom edges of your object, you can do your loft.


I added left the superposition of original and rebuild surfaces to see if this is correct. It seems good.



Curved_Surface_Texture_fx.3dm