I entered a battle with a wild pokemon and received the error, however also noticed that there was, at the top of the screen, a 'stop spectating' button
I clicked it and it let me out of the battle, however my screen began flickering black around where the text boxes should have been.
Is it possible the waiting error could be due to a crossed wire somewhere with spectating?

If spectating and kicked from server, on relog I will receive the waiting glitch during first encounter. 'Stop Spectating' is visible at top of screen even if it is a wild battle with a random pokemon.
Recreated three times.