Adding One SL's Killed my Sub

Bought arc and sub 2 weeks ago.  i could have wept at how incredible it sounded.  added two one sl's last week as rear surrounds.  All was glorious for about 48 hours.  while watching a 4k br friday night (longest possible time to talk to a live support rep), arc made a loud static like sound for a second or two.  arc and sub disconnected.  reconnected arc no problem.  sub was a bear. was able to get incredibly faint sound out of sub after hardwiring arc, but nothing like its potential.  literally 4 hours on the phone with support today. at least 2 dozen diagnostics.  supervisor (who was super nice and genuinely interested in helping me fix things) ultimately told me I'd need to schedule a call with the engineering team (which I found out later was in two days!). kept perusing forum and something clicked to make me disconnect surrounds.  the bass is back in a big and beautiful way! but my one sl's are paper weights.  any thoughts on what caused the issue and how to configure the two rears??