Loose hexagon socket screws on the handle assembly and beam assemblies are the fix.
You need a hex key. Check these points:
- Tighten the 4 hexagon socket screws (part number 202-2) and their prevailing torque hexagon nuts (part number 202-3) where the handle connects to the main beam.
- Check the clamp (part number 202-20) and clamp block (part number 202-5). Ensure their screw is tight.
- Inspect the beam assemblies (part number 202-401, 202-402). Tighten all visible hexagon socket screws (part number 202-19).
- Check the control handle set (part number 202-22, 202-404) where it attaches. Tighten any loose screws.
If that didn't work, the internal structure of the handle assembly (part number 202) may be cracked. Look for stress fractures in the plastic, especially near the switch box set (part number 202-403).
Heads up: Don't overtighten plastic screws. Snug is sufficient.