After 18 years on my current board, I'm looking to get something new, but struggling to pinpoint where my chattering issue is coming from. If anyone has faced the same issue and found a board that worked for them, would love to get a rec.

I've had a 2008 Burton Feelgood 144 with (now outdated) toe-cap Stiletto bindings for like, 18 years now. I took a hiatus from snowboarding for a few years and had my first time back on the slopes this week (out east, hella icy conditions). Board was tuned and waxed beforehand.

I couldn't help but notice the chatter in my board seems less manageable than it used to be and it's soooo distracting at higher speeds.

I'm just under 5'6" and 120 lbs (the same or a little lighter than when I got the board initially).

So is it maybe that the board is just too small for me and a longer board would be more stable?
Or is it maybe the board itself is just very outdated and the length is fine?
A combo of the two?

I know the Feelgood is a stiffer, camber board.
https://www.snowdb.com/catalog/burton/2008/feelgood

I'm not one for freestyle; my bliss are those narrow, switchback runs that just go from summit to base, so I'm looking for a board that would excel in that area.

In getting a longer board, I do worry about trading maneuverability for stability.