Explain Go Code Issue

I’m running into behaviour in my Go code that I don’t fully grasp. Rather than handing the project over, I’d like you to walk me through what is happening, point out the root cause, and show how to resolve it. After I share the snippet (and any error output) I expect a clear, step-by-step explanation of why the issue appears, what parts of the code or build setup trigger it, and what changes would eliminate it. Screensharing or annotated comments in the file are both fine—whichever helps me understand the solution best. The goal is knowledge transfer: by the end, I should be able to reproduce the fix myself and understand the underlying concept, not just copy-paste a patch.