Get rid of the hp and upgrade to an Epson or OkiData printer!
I know your company sells and services oki and epson so you have a vested interest in switching people over, but it's not helping anyone when your go to latex solution is to buy a new printer that have their own problems.
As to the problem at hand... Is it not curing properly in all spots, or just one section? We had the issue and took a thermometer gun.... One of the elements/ sections wasn't as hot as the rest.. A tech swapped it out and the problem fixed. I'd make sure you have constant temp across your whole heater platen. And if it's just a recent problem, give it a good Cleaning. Or you could increase the pass count...it's really easy to do. Just YouTube hp latex create new profile...their tech shows you simple steps on how to do everything. You'll actually get better colors not using a canned profile also.
Of course you can do what Bruce suggested. Throw it out, buy a printer that's twice the price that can print on half the materials, and has a massive head repair cost. But then at least you won't have to spend 10 minutes to learn how to create a new profile and increase the passes. ¯\_(ツ)_/¯