Same thing happened to me on more than one occasion. Just when the next round was about to get started I got swished away to another room, even though the quick match weights are the same for both types of battle (big and medium). Fortunately, the switch did result in a round of play, even though I had to wait 5 to 10 minutes for it to finally start.
Also, I dont really like being whisked away like that. It makes me feel out of control. Computer decides what's good for me?
Sounds like an episode of Little Brittain:
'My wife's in labour!'
'What's your name?'
'Jones'
'Computer says no.'
'But we registered beforehand!'
'Computer says no.'
'Our obstetrician is Dr Phelps, can you page him or something?'
'Computer says no.'
'Oooooohh ooooohh, oh, I think my water just broke.'
'Computer says no.'
'Goddamit, can't you help us?'
'Computer says no.'
'We want to see your manager!'
'Computer says no.'