How do I clear the normal map seams even though I painted over the texture? I have an altar model that I want to texture. I have visible seams, but I paint over them. It appears correct when a map is in the Color node (diff/normal). I save the painted over image, but when I reload as Normal Map Color node, the seams are there, and they are pretty obvious. I've done the same with the normal map (just smudging the seams but it does appear seamless when the map is in Color). Any clues?
Open it in GIMP.
Filters > Map > Make Seamless
File > Export As > Whatever_you_want_to_call_it.png  

Export > uncheck everything > Compression level 9 > Export
Load this normal map w/ node editor, in place of the original.