White vertical lines when saved as a PNG

So I saved a drawing from Photoshop but for some reason these white vertical lines appeared, I tried saving again but it didn't help. These lines don't show while I'm working in Photoshop so I really don't know what is causing this. Anyone know a solution?

The lines are located right on top of the words "flat colour" as well as a thinner one on top of "full colour", the both go down to the turquoise line