Thought of something else. Something I used to unintentionally do when I was newer was overtighten wheel nuts. Not really an issue if you have alloy hexes, but if you have plastic hexes (like my t-maxx did way back when), they get deformed around the pin in the axle and smash into the side of...
Could also be you have something binding in the drivetrain on the left side, like a bearing going out causing drag or twine/string wrapped around the axle behind the hex causing drag.