Also encountered this issue. Internet connection was lost for ~30 seconds causing a disconnect, and ended up stuck at the "Currently Waiting" screen with game sounds playing in the background. Closed and relaunched the client only to end up at the same screen. Was only returned to the main Arena menu after relaunching again after game and match losses were handed out from timeouts.
Ultrathrok#94651
Also encountered this issue. Internet connection was lost for ~30 seconds causing a disconnect, and ended up stuck at the "Currently Waiting" screen with game sounds playing in the background. Closed and relaunched the client only to end up at the same screen. Was only returned to the main Arena menu after relaunching again after game and match losses were handed out from timeouts.