While I don't know the customs in your field, in some it would be reasonable for the PI to be listed first, especially if they were involved in starting and/or leading the study. Or maybe just in providing funding. If everyone else is in alphabetical order then your specific placement isn't relevant. You are just an "S" rather than a "B" with nothing implied about participation.
And, in large collaborations, it is somewhat common for the PI to be listed either first, or last. Customs differ. Readers in the field understand this, more or less.
An acknowledgements section of the paper could detail specifics of contribution if that is desirable.
In some fields (math) authorship is generally alphabetical and people are assumed to be "equal" participants.
Having put fingers to keys doesn't make you first author. I've been in collaborations where one of us did the actual writing but two others were actual leaders of the group and, so, listed first. It was just that the "writer" was a better writer than the rest of us. But he took no lead part in the work.
I advise not starting what are ultimately inconsequential battles with peers, and especially colleagues. The external world will care very little overall.