It seems that you had open stroked paths with varying widths (made varying with the Width Tool, pressure, whatever), and now you have closed filled paths, probably after Object>Expand Appearance or something (which may be hidden in the phrase after saving (you could have downsaved and thereby lost the varying width property)).
Only when you save an ai file in the same version as you work with it you can retain everything. If you save it as an older file type or as svg you get things converted and loose a lot of editablity.
What do you mean with "intermitent" here?
It is an intermittent problem, I will design 3 images and they will be fine but then my next 2 will have the problem. I’m not changing my method of design or steps to save the image. Its seems like Illustrator is automatically selecting “outline stroke” when saving.