Saddle sores

I have thousands of miles bikepacking and had very good luck with Selle atatomica saddles. I have had no issues up to this point with saddle sores but on a recent 350 mile 4 night bikepack trip that I have done a few times, I developed severe saddle sores on my sit bone area. THis happened on the first day making the rest of the trip painful. I was using newer good quality bib and on a relatively newer selle anatomica H series saddle that I did a 120 mile ride on the month prior with no problems. THis is the kicker, I got a new bike a few weeks before ride (ti 29 plus)and set it up with the saddle a little more forward than normal according to fit. I know, rookie mistake tweaking before long ride/race... Nothing else really changed. I unfortunately only did a few 20 mile rides with that set up before long trip. I've never really had problems in the past few years so made some poor decisions with the last minute changes. Im guessing that exposed non conditioned skin on back side causing the blistering on sit bones? Im also hoping that with more miles after healing up and tougher skin building, that will no longer be a problem? Hoping for some reassurance cause I really like the new bike and position. THanks and Happy New Year!!