the report timing between pnr & sta should match at the 10*picosecond without SI. To aligne the net delay, you need to adjust the net delay calculation in PnR versus the STA signoff.
The tool ostrich for example compare the SPEF from PnR versus the spef from parasitic sign off extraction, and generate the factor needed to align.
After this step, the majority of the path should met.
When the SI mode is enable, the engines are different between all tools, but the difference should be inside the margin and not really relevant.