Why does one have a line and the other doesn’t?

Both were taken with first morning urine. One has a line that I can’t tell if it’s a indent or a positive and one is clear as day negative. If it’s an indent wouldn’t I get indents on both the test? Just wondering why both these test don’t have indents after they have been sitting for awhile. So do all of these type of test indent or just some of them?

Picture of today’s test

Picture of yesterday mornings test!