Problems from soundboard to PC

This may be a shot in the dark but I honestly don't know where to turn in order to even understand the problem we're having. I'll do my best to interpret what's going on but just know I won't have all the answers.

I stream a church service every Sunday. Our music director paired with our freelance sound guy were experimenting with the different effects for the music for that Sunday service. Nothing sounded out of the ordinary besides the delay they added to the vocals of the music director's mic. It was subtle but could be easily missed if you weren't paying attention. After everything was said and done I kept getting weird responces from others saying there was a weird echo to the music. I thought they were just talking about the delay that was intentionally added but I needed to check the pastors mic levels anyway and when I played the video there's a very noticeable echo when the music director is playing. It sounds like I'm getting two sound sources on the same level but one has a slight delay.

We want to try and fix it before abandoning the effect all together but like I said before, I have no idea what's going on or even begin to understand what's happening. We have sound equipment that allows us to hook up several guitars, drums, piano and mics and all of that runs to an audio capture box that then runs through USB to the PC.

How can a small delay turn into a huge echo/delay after recording? I have tried fixing the audio in Audition to get rid of the reverb but everything I try makes the audio worse and makes all the talking dialogue to sound lower and softer in the end. Any help would be greatly appreciative.