POE2 Trade site is not calculating flat damage on weaponry

If you sort by most dps, it only shows the %increased physical damage on weapons for bows. Unsure if that's the case for any other weapons, but it is for bows.

Elemental damage is not being calculated whatsoever so I cannot determine if a weapon is better or worse than mine

Had the same issue when searching for crossbows. I think in addition to the flat missing, also the increased damage from runes is also missing in the damage calculation.

Phys DPS was always the same as DPS. So yeah, the elemental additions are missing as well, as you said.