Neutered cats w/ dominance issues

Is it normal for 2 male cats who have both been neutered early to be having "Alpha" issues? Harley is now going on 3 (fixed at 4-5 months) has been a dream...no spraying or territory issues. He gets along with all the cats. Until now. Gizmo, the only other male in the house was also fixed 4-5 months but is only about 7 months old now. He is the only cat that Harley has a problem with. They used to get along fine but now they are constantly challanging each other. Not the normal play-fighting, they don't actually "get into it"...its more like "you are in my space so leave or you'll be sorry". This is VERY uncharacteristic of Harley. Neither of them are this way with any of the others, not even the dogs! Is it because they are both male? I thought neutering would stop any kind of Alpha thing. Has anyone else have this happen?

I don't think neutering eliminates dominance issues, though it does reduce them. Our cat (neutered at 6 months, now over 7) even marks when he's outside, and will attack any other cats who get on his "turf".
I'm sure you're going to get a lot of answers from members with multiple neutered cats who will tell you that there's still a "pecking order".

There will always be a pecking order in your house, regardless of whether or not they are neutered. Neutering does calm them down a lot, but dominance is very much instinctual.

I've noticed that the biggest problems that I've had with pecking order issues are early teen age (7-11 months), early adulthood (2-1/2 to 3-1/2 years), and when an existing alpha hits his geriatric years, particularly if they are ill. Most times the cats simply work it out and within a few weeks or months life is back to normal.

All my cats are fixed - 5 girls, 6 boys. The dominance issues have never disappeared. Best not interfere.