Hello, there is one infinite light and one ibl light - both set to 100% white

1. pls take a look at the picture where the wall meets the floor - as you can see shadows are not aligned - is there a way to make it right?

2. wall and floor are 100%  white but I can get them white only if the light is 45deg on xRot  (in half way between them) - each deviation from that gives me gray color on one of them - is there a way to make them white while the infinite light is at different deg.?

Thanks.