Just bought an RE220 in order to extend home network and allow my home speaker set up to be played at the bottom of the garden.  This seems os have worked for the speakers however the rest of the home wifi doesnt work as well - constantly dropping signal and becoming really slow!

My set up was to give the range extender exact same SSID as the original network in order for the speakers to only "see" 1 network. Is this my problem?  Any idea how to fix this?