I have had problems with a completely uniform grey tint on Oriental graded paper. I have 8x10 and 11x14 boxes of grades 2, 3 and 4 - the problem is only with grade 2 in both sizes.
The tint is there if I process the paper in complete darkness, it doesn't decrease if I add bromide or benztriazole to the developer, and it can't be bleached out as highlight detail disappears before the tint.
Pretty obviously a problem with the paper emulsion.
But I have no idea if this is the same problem the OP is having. A safelight test [or processing a bit of paper in darkness] is the first action to take.