I had a problem with one of my projects that was very simliar to yours. For the longest time I thought my MC’s problem was NON-ACCEPTANCE, but nothing seemed to line up with that approach, especially since her response seemed to be PURSUIT (trying to earn acceptance by pursuing unreasonable standards for herself and, later pursuing what she thought would make her happy) After further thinking, I considered AVOIDANCE as the problem since the reason she felt unaccepted was that others seemed to be avoiding her. But no matter how I tried to twist it, PURSUIT was definitely her response and not her solution.
It was only when I looked at the final resolution that I realized that her trying to CONTROL her behavior by acceping others standards was the source of her unhappiness and that by returning to her previous response of (UNCONTROLLED) PURSUIT of what she wanted, that she ultimately forced the IC and the OS characters to RECONSIDER what was best for her.
(I think it is interesting that the quality of her response also contains her solution. I wonder if this is often the case with steadfast characters.)
When the storyform showed me that her IC abandoning her response of SUPPORTing those same standards of behavior and resolving their relational conflict with the solution of OPPOSING those standards and those people who were trying to enforce them, that I felt I finally had the right storyform.
Regarding Growth, I think I read somewhere that if the story Judgement is Good, then Start means the MC is pursuing their problems while Stop means the problems are pursuing them. If I remember this correctly, that may help you figure out which is the correct growth for your MC. I know I struggled over this. I think Steadfast characters are just harder to figure out in general, but in my case, this story is part of a big novel with two MCs and blended storyforms so it’s sometimes hard to tell which issue belongs to whom.
What still puzzles me though is why Steadfast MCs share the symptom/response with the OS, especially since it seems that Steadfast MCs are in conflict with the OS, trying to force both them and the IC to change even though their response to the perceived problem is the same.