F1's governing body is making adjustments ahead of the Bahrain grand prix so that drivers at the back of the grid can see the start lights.
"I could only respond when the cars started around me," Gasly is quoted by Germany's Sport1.
And Kubica added: "I panicked initially because I could not see the lights.
"The rear wing of the McLaren obscured it."
A spokesman for the FIA told Germany's motorsport-total.com that what happened was "an unintended consequence of this year's larger rear wing".
A solution is currently being worked on.