Helpe diagnose a front end noise?

Hi folks. I have a 2017 Ram 3500 with 135k miles. I am currently running 37s on 20 inch rims with a -19 offset. I recently switched from 35s.

I have a very intermittent humming/vibrating noise that I can feel in the steering wheel. I cannot for the life of me seem to get it to duplicate, but I can tell it's getting worse. Sometimes it happens when I'm making a right hand turn. I happened today when I drove over some railroad tracks. Sometimes it happens when I'm going 5mph and sometimes it happens when I'm going 40mph.

I thought it could be my front differential, but I just had it serviced and they said everything looked fine. No metal shavings in the fluid or anything. I'm still not ruling the front diff out though.

I recently had my transmission serviced and everything looked perfectly fine there too.

I have absolutely zero slop when I check my wheels on jack stands. My alignment is fine. Tires aren't wearing unevenly from what I can tell.

Any ideas or things I could check would be very much appreciated!