There are four instances of ἐν πνεύματι in the book of Revelation:
9 I John, who also am your brother, and companion in tribulation, and in the kingdom and patience of Jesus Christ, was in the isle that is called Patmos, for the word of God, and for the testimony of Jesus Christ.10 I was in the Spirit ἐν πνεύματι on the Lord's day, and heard behind me a great voice, as of a trumpet, 11 Saying, I am Alpha and Omega, the first and the last: and, What thou seest, write in a book, and send it unto the seven churches which are in Asia; unto Ephesus, and unto Smyrna, and unto Pergamos, and unto Thyatira, and unto Sardis, and unto Philadelphia, and unto Laodicea. 12 And I turned to see the voice that spake with me. And being turned, I saw seven golden candlesticks;
-- Revelation 1:9-12 (KJV)
So, John was on the isle of Patmos (v. 9), then is "in the Spirit" (v. 10), and then he is transported to a place amid seven golden candlesticks, where he is spoken to by a voice like a trumpet -- the voice of Jesus (vv. 11-12).
The next two chapters, Revelation 2 and 3, are the messages Jesus gives to John for the seven churches, while he is standing amid the seven candlesticks.
1 After this I looked, and, behold, a door was opened in heaven: and the first voice which I heard was as it were of a trumpet talking with me; which said, Come up hither, and I will shew thee things which must be hereafter. 2 And immediately I was in the Spirit ἐν πνεύματι: and, behold, a throne was set in heaven, and one sat on the throne.
-- Revelation 4:1-2
After hearing the messages to the seven churches, John sees a door open in heaven (v. 1). He hears a voice say, "Come up here." (v. 1), then he is "in the Spirit", and transported "up" to where he had just been invited, into the presence of the throne of God (v. 2).
1 And there came one of the seven angels which had the seven vials, and talked with me, saying unto me, Come hither; I will shew unto thee the judgment of the great whore that sitteth upon many waters: 2 With whom the kings of the earth have committed fornication, and the inhabitants of the earth have been made drunk with the wine of her fornication. 3 So he carried me away in the Spirit ἐν πνεύματι into the wilderness: and I saw a woman sit upon a scarlet coloured beast, full of names of blasphemy, having seven heads and ten horns.
-- Revelation 17:1-3 (KJV)
All that John has recorded up to this point, Revelation 4:3-17:2, was shown to him while he was in the presence of the throne of God. In 17:3, he is once more "in the Spirit", then transported into the wilderness (back to earth) to see the woman on the scarlet beast.
9 And there came unto me one of the seven angels which had the seven vials full of the seven last plagues, and talked with me, saying, Come hither, I will shew thee the bride, the Lamb's wife. 10 And he carried me away in the Spirit ἐν πνεύματι to a great and high mountain, and shewed me that great city, the holy Jerusalem, descending out of heaven from God,
-- Revelation 21:9-10 (KJV)
The things John records from Revelation 17:4-21:8, are shown to him while he is in the wilderness, then in 21:10 he is "in the Spirit", and transported to a great and high mountain, where he looks down upon the New Jerusalem.
The common idea being expressed in these four instances, by the phrase "in the Spirit", is that of transportation:
On Earth --> Amid Candlesticks --> In Heaven --> On Earth --> On Earth
(Patmos) (Wilderness) (High Mountain)
There is no break in the sequence of the Revelation, only changes in location while the sequence is being revealed.