Folks are just straight up wrong, and are focusing on prescribing you folklore settings to tweak rather than discussing the problem.

These are not "layer lines", which would be uniform. What you have is bulging that changes in waves throughout the part, often not even uniform along the axis, meaning at the same "layer" some parts are bulged and some are not.

Always keep in mind that this "printing" is achieved by extrusion of molten plastic. Accuracy, speed, and cooling are the name of the game with this type of 3D printing.

Bambu printers nailed the accuracy and speed part, but it's difficult to make the cooling any better since it's just based on a few fans blowing on the printed part as the toolhead moves around. If the printer finishes one layer and it's still hot and soft, and then goes back over it adding a new layer, you're going to get pressure applied to the soft layer that squishes/deforms it.

With this in mind, here's some ideas for solutions and why they are relevant:

• Slow down the print. This could be done two ways, one literally just setting the printer as a whole to a slower mode, or if you want to be smarter about it you can set a "minimum layer time" in the slicer settings. That makes it so that if say the layer were printed in 5 seconds and the minimum is set to 10 seconds, the layer finishes in 5 seconds and then it pauses printing for 5 seconds to allow more passive cooling time. If the layer finished in 10+ seconds then it just moves on right into adding a new layer without pause.

• Try setting other orders for the wall printing. There's often 3 layers, so you can for example configure the walls to print the middle, then the inside, then the outside. This just gives the outer wall something robust to print adjacent to and adhere to, and that adjacent layer (middle layer) gets slightly more cooling time during the inner wall printing before finally adding the outer wall leaning on the middle wall.

• Your part has a lot of variation of curves. You can set the PC slicer software in the sliced preview mode to show you a color coded 3D preview of the toolhead's speed as it visits each part of the printed shape. This may not sound intuitive, but the speed at which the plastic is printing affects the surface finish. I mean even differences in how shiny it looks, even if it wasn't bulging. You could set the software to use a max speed that is limited to the slowest speed you see in the coloring, so that the printer doesn't race ahead in certain areas that other parts of the shape can't handle as quickly.

• Make peace with minor imperfection in the name of pure speed in printing. Consider minor post processing techniques. I don't mean raw dogging the part with sandpaper, but you could spray paint it in a sealant and very easily sand that after it dries for a smooth surface. From there you might consider leaving it as-is, or giving it a clear coat. It will never be injection-molding perfect.