XPS 9343 wi-fi slow connect

Running XPS9343 Win10 x64. Everything working fine apart from problems connecting to new available wi-fi signals even though they are 'full strength'. Eventually it does find them and connects but in the meantime shows no wi-fi available. 

Once connected then it stays connected whether the XPS is shut down or sleep mode - it always finds the last wireless it was connected to - zero delays in doing so. But move to a different area with a different wi-fi signal then it's back to the no wi-fi available.

Any suggestions/input appreciated.