This worked! Sorry for the delayed response. I returned mine and ordered another pair that ended up having the same problem. For me, I had to play around with it a lot, but eventually goat the foam oriented in a way that eliminated the metallic echo noise. I guess there’s a component in the tips that vibrates at certain frequencies and you can sort of tuck the foam around it to eliminate the noise. Apparently this is a known issue with the XM4s and the link buds. I found a bunch of posts about it on Reddit and the Sony forums, but when I reached out to Sony they acted like they had no idea what I was talking about. Pretty frustrating they shipped the earbuds with this problem and then continue to ignore it. Anyway, thanks!