How do I get rid of those two thick lines, or what is causing them?
Try cleaning your build plate with regular dish soap and water. Avoid touching the build plate because oils from your hands get on it.
That’s the top surface, correct?
If so, look at your preview in Bambu Studio - the first solid layer after the infill likely isn’t bridging properly in that area. Change to a different infill, bump up your sparse infill density, and you may want to add another top layer or two.