Having issues on my 2019 Mule pro fxt ranch edition. Driver side tire is leaning in. Tire is getting terrible wear on it. Changed ball joints and check bushings. Adjusted toe issues.Still have problems. Could the A arms be off from factory?
The first cause for negative camber angles on a UTV are warn a-arm bushings and/or ball joints but you say that's all to spec. The next most common reason is the use of a lift kit but that would effect both sides. The third reason is a change in caster angle..and that's most often due to a bent a-arm or frame near the mounting points. And that's most often due to an impact with something like a stump, rock or something not very moveable or the unit had a problem rolling over. Has anyone besides you drove it lately without your attendance?
Like @NMKAWIERIDER mentioned....I'm guessing you have something bent. Likely an A-arm or tie rod. Could also be worn bushings. We make adjustable A-arms that allow you to adjust your camber wherever you want it. They also offer more ground clearance and are forward offset to allow for bigger tires. You may also want to check to see if one of your tie rods is bent.
Here's a link to the adjustable arms.