Very curious to hear any follow up to this.
My (brand new) remote disconnected AND crashed the whole system the other day while I was just programming the Kemper in my studio...not even in a stage setting.
The one thing I might add is that, right out of the bag, the captured ethernet connector (on the shielded connector end) of my supplied cable wasn't quite right... the ethernet connector RJ plug inside had to be kind of forced into the right internal position or it wouldn't even plug into the Remote... so I had a slightly funky cable supplied to being with (from the Kemper US Store directly).
But that still doesn't prove it was the cable' "fault".... although it makes me suspicious when coupled with your story.
did Sweetwater fix your issue with a new cable?
thanks in advance
I am thinking I should order a back up cable to be 'safe'