wi-fi doesn't connect when undocked from docking station - dell laptops

Hi all

we have a situation at work where , when a user disconnects from the docking station to run to meetings, the laptop (e7450), (e5550) , just loses connection to the wi-fi, and the only work around is rebooting, or, getting to a LAN point, and doing a gpupdate/force

Can you please point me in the right direction?  I have checked bios settings, I have updated wireless drivers. it still disconnects, and then we have to rush into boardrooms full of angry users, lol, dreaded situations, to try and quick-fix the issue.   any help would be appreciated. 

thank you very much