Opera 56 close/minimise/maximise traffic light buttons unresponsive unless app foremost

[sqeeezy]

sqeeezy last edited by

Retina MacBook Pro late 2013/10.14.1 Beta (18B45d)/Opera 56/ no extensions enabled. I think this is a recent anomaly. I haven't found any of my other apps to fail to respond to clicking on the buttons when app is in background. I have googled and skimmed through the posts here. Any help much appreciated. Cheers.