Welcome to the vog and the new to you Vision.
a couple of things to check/be aware of.
exhaust. Yes, could be just a recore from WD or Miller or Ness Big Honkers. If you want them quieter, your best bet is to have them reworked by Ragin Cajun. On here as @crosscountryla
He has reworked more mufflers than anyone and has more happy customers than you can shake a stick at.
is there a power commander on the bike? Usually under the panel right in front of the seat or the side panel under the right side of the seat.
Vics do NOT like low rpm. Keep RPMs at 2500+ (yes, even at slow speeds as much as possible) to avoid the “chug”. you are likely lugging the motor.
if elevation or weather has changed, you can do the IAC and TPS reset procedures just to make sure. Do a search on here for how to do them.