In my test I got the old and new switch green and fine in the dashboard, configured the two QSTP ports as stacking ports then connected the two QSTP stacking-cables. Few min laters I the switches disconnected from the dashboard and lit up orange.   Decided to pull the power on the new switch to recover, then soon the production switch came back online again.   Both switches are connected to the MX, and although you create a loop by connecting the stacking cables, the ports are defined as stacking ports, and also RSTP is enabled so not sure if that is the cause.   Should I just have more patience and have waited?    Anyone with some experience on this?   Can you stack two switches during production or does it require downtime? ... View more