Garageband and Scarlett 2i4 audio interface

Since exporting a file from zoom H4 essential, to garageband... my input drivers changed from "Scarlett 2i4" to Zoom. My internal speakers stopped playing the recording. I went to "settings" and changed from Scarlett to "system settings". The internal speakers work, but now I'm getting a lag when recording..? I've used this set up 4 years with no trouble; until I used that zoom recorder;~( Help?