Sorry everyone for the delay in replying. I've been really sick with a cold and haven't been up for beer talk.
@sneezles61 - I did this batch on my stovetop (natural gas) and use a temperature controller thromostat as a thermometer since it has a wire temp prop that can just hang in the mash. Because the whole thing was kind of awkward I very well could have had hot spots with trying to maintain my temps for an hour (plus the 10-min sacch rest).
Prior to posting this question, I had also made a 5-gallon BIAB using NB Kama Citra kit and doing this on a propane burner because I felt daring. This batch also has a hint of that bitterness but nothing at all like the Dead Ringer. I had nowhere near the issues with keeping things up to temp but I'm sure there was some error on my part as I was new to dealing with this propane burner (that gets up to 110,000 BTUs!!). I used that temp controller as a thermometer for this batch as well.
So now I will get my water tested and go from there. I will revert back to doing 3-gallon batches until I get this figured out.
I really appreciate all of you chiming in with your thoughts on this!