In this answer to the question "Are angels free-willed, perfectly ethical beings?" the conclusion is:
the angles are not independent in will and power. They always do what Allah orders them.
Does obeying Allah in everything really mean one doesn't have free will?
We believe the Prophet had free will and we believe he obeyed Allah in everything.
This hadith, seems to contradict the idea that angels doesn't have free will:
Narrated Ibn 'Abbas: that the Messenger of Allah (ﷺ) said: "When Allah drowned Fir'awn he said: 'I believe that there is no god except the One that the children of Isra'il believe in.' So Jibrail said: 'O Muhammad! If you could only have seen me, while I was taking (the mud) from the sea, and filling his mouth out of fear that the mercy would reach him.'" Jami Tirmidhi : Classed Hasan
It is clear that Jibrill decided to put mud in Firawn's mouth by his own free will; by the wording "out of fear that...".
The angels asking Allah if he will you place a mischief makers (Adam and his descendants) on earth, seems to indicate that they have free will, at least to ask questions:
Quran 2:30 And [mention, O Muhammad], when your Lord said to the angels, "Indeed, I will make upon the earth a successive authority."
They said, "Will You place upon it one who causes corruption therein and sheds blood, while we declare Your praise and sanctify You?" Allah said, "Indeed, I know that which you do not know."
With this mentioned, why do Muslims believe angels don't have free will?