Canyon Grail headset play
Just tightening the screws will not resolve the issue. There is a precise but quite simple procedure to follow. You can find a number of very good explanatory videos on the internet. GCN has a recent one on unboxing that specific bike that might be useful.
The usual procedure takes three steps:

Undo the pinch bolt(s) on the stem, normally two, left and right on the stem by one turn

Tighten the top bolt until play disappears while the bar still moves freely from side to side. This requires some sensitivity.

Tighten the pinch-bolts with the recommended torque!!


Then recheck the free movement of the bar and re-adjust if required.