This is normal and part of the chair’s ergonomic design. The armrest and rear support rod need adjustable clearance to accommodate different positions and usage scenarios, so a visible gap is intentionally built into the structure.

This design helps prevent binding during adjustments and ensures smoother, more effective movement. It is not an assembly issue or a quality defect. Please feel free to use the chair with confidence. If you have any further questions, we’re happy to help.