Opening windows dumped to main display after disconnecting extended display

[qiusli]

I'm using a mac and have a two-monitor set up, one main monitor and an extended display which is in vertical mode. Each time I disconnect the extended monitor all the active windows there got dumped to the main monitor. Next time when I reconnect the extended monitor, I'll have to manually move all the windows back there. Is there a way to prevent the dumping behavior upon disconnecting? ty