Zirr bin Hubaysh reported,

I said to Ubayy, "Your brother erases them from the mushaf," and he did not object.Sufyan was asked, "Do you mean Ibn Masud?"He replied, "Yes. They are not in the mushaf of Ibn Masud. He used to see the Messenger of Allah ﷺ seeking refuge with them for Hasan and Husayn, but he never heard him recite them in any of his prayers, so he assumed they were merely two formulas of seeking refuge, and he held firmly to his assumption. The rest of the Companions, however, verified that they were part of the Quran and so they included them in it."

حدثنا سفيان بن عيينة عن عبدة وعاصم

عن زر قال

قلت لأبي إن أخاك يحكهما من المصحف فلم ينكر قيل لسفيان ابن مسعود قال نعم وليسا في مصحف ابن مسعود كان يرى رسول الله ﷺ يعوذ بهما الحسن والحسين ولم يسمعه يقرؤهما في شيء من صلاته فظن أنهما عوذتان وأصر على ظنه وتحقق الباقون كونهما من القرآن فأودعوهما إياه