Mercedes is working to fix a problem that leaves Valtteri Bottas with leg numbness while driving the otherwise-dominant 2020 car.
The Finn admitted at Spa that there have been "a couple of races" this year when his left leg begins to lose feeling.
"It's difficult to say how much I am affected, but it can lead to mistakes," said Bottas, who is 50 points behind his teammate Lewis Hamilton in the drivers' championship.
He told Speed Week at Monza: "The team is in the process of finding a solution. They listen carefully to me.
"As a driver it's essential to feel comfortable in the car, but we still don't have a solution here in Italy.
"We spend a fair amount of time in the car, so it's important to make improvements," Bottas added.
