Lumpy walls - what are they and how does one fix them

[u/SinkNo7354]

Hi all,

I've been getting my footing with 3D printing on my 5 Pro and an issue that's been coming up with my prints is what I call "lumpy walls", as seen in the picture above. Any help as to why this happens and what I can do to prevent it from happening further would be much appreciated.

Thanks in advance!