Also, the ‘best answer’ stated on this discussion - That one should update from 17 to 17.1 - does not appear to be constructive.
A constructive answer would far more accurately represent the reality of the feedback. In this way it would be more honest and therefore more useful. A best answer would therefore be more like this:
The issue appears to be not with a new phone but with the new operating system iOS 17. While a few have said 17.1 fixes the issue, others have said it does not and the issue persists with all iOS 17 updates (so far up to 17.1.1).
For this text message editing issue, a workaround, while far from ideal, has been to ‘select all’, cut and paste into ‘notes’, edit, paste back into messages.
It has been stated by users that the difficulties with the cursor in the messages app are not isolated to the messages app. The cursor has been found to be hard to control elsewhere when operating iOS17: such as when writing in this forum - e.g. one taps in a location of text and the cursor refuses to go there or it selects text that one does not wish it to.
However, when writing in ‘notes’ there is no issue with the cursor in iOS17. It works normally just like in iOS 16.
In summary the problem appears to be fairly broad around the cursor - cursor problems showing themselves in a number of apps/interfaces when one is using iOS17.
It appears that this problem has not yet been resolved by Apple.