Small oval shaped repair showing through basecoat??

[robbocop33]

Never had this before.Just paint everything myself with good quality spray cans and "usually" get great results.
However,repaired a small part of my motorcycle tank,then painted it with the basecoat black,when it dried i saw the oval shape of the repair through the basecoat?
No bloody way i thought,repair was smooth as hell,i always take my time.So i thought bugger it,flattened it again over the repair,painted it again with the basecoat,it's still bloody showing the very edge all round the repair?
Why is this happening?,there is no risen edge to my repair.

[finlo]

Shrinkage, the paint can cause the filler to shrink.

[227bhp]

Needs a picture really, could be as said - filler shrink or a paint reaction.

[paintman]

^^^
Possibly edge mapping/edge marking.

[Squiggs]

paintman said:

Possibly edge mapping/edge marking.

This.

Bike tanks often have a good build of lacquer so you're sanding off a lot of product causing a dip.

[V8covin]

Did you prime over the repair ?

[robbocop33]

Bit of an update,i put a good few coats of lacquer on top of the basecoat,once hardened i concentrated on t-cutting exclusively on the edges of this oval ring edge,and bugger me it's slowly disappeared and become virtually invisible??
Don't know how but it just has,lacquers amazing stuff,hides a multitude of sins! ;-)