convex collider of plane is much bigger than gameobject

hey everyone, i have just updated my Unity and now it is Unity 2019.3.0f6 personal. Everything was okay in previous version but when i import my project in updated one , a Gameobject(Plane) behaves differently . I mean , i need a trigger collider on my plane so i had to go for convex collider because there is no option for Is trigger with concave collider , but now the size of convex collider is much bigger than gameobject and it seems like it is a collider of a 3D Cube or box . If anyone has some solution for this problem, plz reply …because there is no option for editing size of convex collider of plane …
sorry for my bad english

Maybe Change to a box collider, then change the scale to fit the plane.