Hey. I've installed it on two separate machines, one had no Cura on it previously and the other had the Eleegoo version (which is 60°). On both, it is setting my build plate to 70. Could it be a problem with the Neptune 3 Pro hot end settings in 5.6, if you're not having the problem?
As you can see from the screenshot. Those ARE the defaults even after clicking to reset them.
I can assure you 100% that it was defaulting to 70 and I would never play with those settings, even accidentally, as 3D printing still somewhat scares the hell out of me!