Change thickness of Checkbox tick ANTD

Following up to this question: Change color of tick in ANTD Checkbox

Now I want to change the thickness of my tick. This is what I tried:

.ant-checkbox-checked .ant-checkbox-inner:after {
  border-color: red !important;
  border: 5px solid #0080000;
}

However, this is my output:

I still don't get why this is happening, can anyone please explain?