I cannot create a goddam dimension between two lines on a Drawing

The first one (step 2 on the picture) is a geometry (from a section cut). The second line (step 3 on the picture) is a sketch line created on the drawing

Happens everytime. Been dealing with it pressing Ctrl+Q or closing the program and reopening it. This time is not goddam working

When Not under a Smart Dimension, the line is black and I can manipulate it normally