Machine weight stacks move in fixed pin increments, so a target like 20 kg might only be reachable at 20.412 kg on that particular machine. When you log the actual pin you used, it can differ slightly from the target BulkForged suggested — that's plate granularity, not an error. The app's progressive-overload engine compares the weight you actually lifted, not the exact target number, so a close-but-not-identical weight is handled correctly.