Yes I think “settling in” explanation makes sense.
During one of last week’s rides I had the 530 giving a data uploaded/synced message every minute or two at the start of ride. Fixed it by removing the RS200 from Garmin Connect Mobile app on my iPhone. While on the phone I also brought up the strange L/R balance stuff. Support rep had me reset the 530 to factory defaults. Had wanted to do that anyways, a bit of voodoo but in my day job that is a legit debugging step. Spent 20 minutes reconfiguring all my screens and despite taking 20 minutes, happier about that part of the post factory reset dance.