I don't see you on the bike but your saddle to bar drop seems pretty usual for an aero.
Take into account that the chiner's frames are known for being rigid and rough.
Moreover the a22 doesn't seem to have a compliant rear according to the frame design. Added with an aero post and high profile rims, it makes you take all the road imperfections directly in the back.
If not done try to put the maximum tire size you can, tubeless and the lowest rideable pressure. Try a dampening saddle, 3d printed? You won't change the frame to a more compliant one but it can help.
In the life avoiding stupid postures or carrying heavy loads without attention helps too.
If nothing works then change for endurance road bike (like giant defy)