In case that this can help anyone in the future, wanted to layout the steps I took
1. An engineer friend of mine said the problem was mechanical/physical since it only creeped up during certain frequencies and loudness. Also some notes around that frequency.
2. Bang on the amp! Try to find the most sensitive area first (wide angle)
3. Use wooden spatula and top on components inside the board until you find the most microphonic/sensitve one
4. 2x capacitors on the lower board were the most sensitive to tapping, I found
5. Disassemble the board and remove
6. Reflow solder to all connections in that area of the board
7. Reconnect and test
8. Problem solved!
* Looks like the area directly behind the speaker magnet is getting more abuse from playing, transport, etc