Dealing with negative carrier halos

I haven't noticed this issue in other darkrooms I've worked in, but having now set up my own space I am getting some significant halo effects around the edges of my 35mm negative carrier. This is impacting my ability to print to the edge of the negative, as the print will end up with overexposed, hazy borders unless I crop in. Before I go filing the carriers, is there anything else I should be looking at?

-The enlarger is an Omega D5XL with a Super Dichroic II color head. The light circle with no negative carrier installed looks correct to my eye.
-I have glassless carriers which are intended for the smaller Omega D-series, but my understanding is that they should work with the D5. (They have the pin holes for registering rather than the circular dish/bump out that I think the D5 carriers have.) They are unpainted aluminum which made me wonder if reflections were causing a problem.
-The only other idea I've come up with is that the lens bellows is not at the right position - none of the documentation I've been able to find shows how to do the rough adjustment on this enlarger.
-I checked the negatives and they're all crisp and properly exposed to the edge of the image. I printed a couple on a different enlarger and did not have an issue there.

backseatpilot said:

They are unpainted aluminum which made me wonder if reflections were causing a problem.
-
-I checked the negatives and they're all crisp and properly exposed to the edge of the image. I printed a couple on a different enlarger and did not have an issue there.

Click to expand...

On the different enlarger was the only difference that the negative carrier was black? Is so it suggests to me that that may be the problem

I had thought that all negative carriers were black for the very reason of what you mention

pentaxuser

Yes, I have some grey reflective metal negative carriers and the reflectivity around the borders could be a problem.

Try applying a very thin coat of rustoleum black paint to the edge with a foam q-tip.

Sorry, I realized on re-reading that I worded this badly. The edges of the print come out hazy white, not overexposed (darker) like I originally wrote.

So the edges are slightly out of focus because the focus is on the negative? If you stop the enlarger lens down more, I assume the edges get crisper. Others may be able to help you better if you post a photo of the carrier.