Sakkaya ditthi is explained in MN44. In that sutta, but many others, it becomes perfectly clear that sakkaya ditthi’s are identity-views like: “i am the body”, or “the body is mine’. Or, “i am feeling, or ‘feeling is mine’. This repeated for the other khandha’s too. There are also other sakkaya ditthi’s but i belief these are the main and most recognisable ones.
So, as long as one sees rupa, vedana, sanna, sankhara, vinnana as Me or mine the first fetter of sakkaya ditthi is still present. The consequence is that when changes happen in rupa, vedana, sanna, sankhara and vinnana and one sees these as Me of mine, one gets afflicted, many sutta’s teach. So, to end this affliction one must see with wisdom and see one is not rupa, vedana, sankhara and vinnana nor are those ours. many sutta instruct us to see rupa, vedana, sankhara, sanna and vinnana like this: this i am not, this is not mine, not myself’.
SN22.89 explains that once sakkaya ditthi has endded one has no views like this anymore: “I am this”…with regard to the khandha’s, but there still lingers a conceit “I am” in regard to the khandha’s. That had not ended yet.
That will end too when one keeps contemplating rise and fall of the khandha’s.
I do not know what is your problem with this. It is just described in the sutta’s that grasping rupa, vedana, sanna, sankhara and vinnana as me and mine, happens all the time. It is it one of the main causes for affliction/stress. The asava of views created these affliction.
An arahant is described as a person (or better, mind) without I-making and mine making.
Changes in rupa, vedana, sanna, sankhara and vinnana do not afflict that mind anymore.
Even if the body would fall apart due to poison of a snake, a sutta shows, mind without I and mine-making does not become disturbed. Mind without I and mine-making does also not perceive “I now enter this or that jhana” or “I now leave this or that jhana”. A sutta tells this was how Sariputta experienced it. He was totally free from I and mine-making. A true arahant.