Perhaps this is because HPS Pythia extended the orb for major aspects to 8 degrees, which AstroApollo and other astrology sites do not account for. HPS Pythia mentioned certain aspects in my Natal Reading too that the astrology sites did not show, likely due to this difference.
HPS Pythia mentioned:
"Personally, I have always used for interpreting birth charts:
For conjunctions, squares, trines and oppositions 8-9 degrees
For sextiles 6 degrees
For inconjuncts 5 degrees
For semi-sextiles, semi-squares, sesi-squares, quintiles 1 1/2 degrees.
In some cases, as with synastry, if there is a Saturn aspect to the ruler, of which I already posted on, it is best to use caution and widen the orb, even the sign, such as opposing signs i.e., Scorpio/Taurus, and signs that square i.e., Libra/Capricorn. But as for doing birth chart interpretations, I have always used the above."