Serpent's Spine Mine - Iron XP Issue

I have been mining a lot of Iron recently at various locations, and have come across a problem with the Iron nodes in Serpent's Spine Mine.

Normally Iron gives 500xp per node, but in the case of SSM the Iron is consitantly only giving 300xp per node.

I don't know if this is intentional, but Iron in Spectral Mines gives 500xp per node, and that is a 4 skull area as well! And I believe it is even 500xp per node in Owl's Nest Mine, which is a 3 skull area.

I also had a friend port to me to check the rates for him too, and it was the same. 300xp in SSM and 500xp in other locations.

Anyone found any other places around the world, where XP from nodes don't add up to what they should be?

Keep on with that Sota time peeps! Hehe!