Printing neutral grays is not the Latex's strong suit. I'm not a color management expert. I hired an expensive one to custom build profiles for our Latex. They worked pretty well, until the printer kicked them out and put back some kind of generic profile. Color management expert shrugged his shoulders and says it's the printers fault. I've learned to deal with "good enough" by just creating new profiles on the printer. Since I don't know how to create profiles from scratch, what the Latex gives me is better than nothing. I just wish they would improve it.
Which latex do you have? I've heard during updates... It'll reset custom profiles back to OEM defaults for media downloaded via the media locator. Which is why I've heard it's best to clone a profile so you dont lose your ICC. And now I'm hearing it's best to start a profile from scratch.. so if you're using one with a built in spectrometer, I'd try making a brand new media. Might turn out better than why you have now.