If you feel the WideWheel front stem has a little play, fist try to tighten the folding knob and ensure the five bolts underneath the knob are tight. If you feel these bolts become loose while riding, you can use a little bit of low strength lock tite.
In case this does not fix the issue, it is possible that the rubber washer above the neck bearing has worn out or is insufficient.
We recommend to replace the washer with a 25mm / 1 inch diameter O ring.
(we have used 1 3/16 inch outer diameter and 15/16 inch inner diameter, and 1/8 inch diameter)
Have a look at the instruction graphic below and this video: