I would try one simple test first...
If you have any spare hammer tips, replace the tip for the note in question with a softer tip to see how it changes.
If you do not have any spare tips, then remove the entire tine and tone bar for the note that sounds too bell like. (the 2 long screws w/springs)
Then, swap it with a tine to the LEFT (one with softer tips) that sounds good to you, just within a couple notes away. If the tine in question suddenly sounds better, then it means that likely you want to replace the hammer tip with a softer tip. If not, the tine may need replacing.
I really feel the tip hardness is the issue.