So you do your 1 minute hop edition then let sit for 30 minutes then whirlpool then let it sit another 30 minutes? if so there is your problem IMO, you have had your bittering hops in for 2 hours and your 1 minute in for 61 minutes.
I no chill pretty much 100% of the time, every now and then in summer, I will throw the cubes in the pool and have a swim with them for an hour or so then throw them in the fermeezer.(slow chill)
I had problems early on with beers being overly bitter. My process is now
bittering edition is no earlier than 45Min from end of boil.
Any other editions are done between 20 and 0 minutes from the flame out.
I turn the heat off the kettle, then add my zero edition/flame out hops.
Give it a good whirlpool for 2 minutes.
Put the lid on then then drain to cubes 15 to 20 minutes later.
Cheers