I noticed that on Sefaria that there are two Hebrew versions of the Mishnah: the Rasash and the Gemara version. For Mishnah Bikkurim, the two versions seem substantially different. For instance, Mishnah Bikkurim 4.5 in Rashash, discusses androginos and describes prohibitions on slavery of androginos, but the corresponding parts of Bikkurim in the Gemara version are phrased differently and do not mention slavery. What is the origin of these differences, and how are they normally treated? It appears that most of the commentary and the translations use the Rashash version.
As the introduction to the Yad Avraham artscroll Mishna notes, chapter 4 is included in the standard editions of the Mishna but may not be part of the Mishna at all. According to many commmentaries, the Mishna ends with chapter 3 while the following chapter comes from Tosefta 2:2-6. This is consistent with the count of the chapters of the Mishna in Rambam's introduction which works when excluding the last chapters from Bikkurim and Pirkei Avot.
That is why most commentators (Rav, Rosh, Rambam) and the gemara exclude this chapter of Bikkurim. They explain later that the unique character of the chapter manifests itself further through different versions of the text across different editions, leading to the difference you note.