This guide applies in case of getting visible seams in 360 panoramas where the edges meet (e.g. between the faces in case of cubic projection, at the poles and one vertical seam in case of spherical projection).
Solution:
Go to Render Setup > System > Frame Buffer and change Image filter > Type from "High Quality" to "Tent".
No other changes are required.
The issue appears because currently (Corona Renderer 5) our High Quality image filter is not compatible with panoramic renders. We are planning to fix this as soon as possible.