Am I misunderstanding this?
Yes, because I wasn't suggesting they were residing in the Temple (if that's what you were understanding).
I did some research and this is what I found about the Upper room (the image got cut off - but the Upper Room is shown at the southern most part of the image by Caiaphas's home):
Quoting Franciscan Media:
The Upper Room, also known as the Cenacle, is located in the southern part of the Old City of Jerusalem on Mount Zion, and is perhaps best known as the traditional site of the Last Supper. The current structure of the room dates approximately from the fourteenth century, which accounts for the existing Gothic-era columns.
According to tradition, this is where the apostles stayed when they were in Jerusalem. It is where the Last Supper took place. The Cenacle is where Jesus washed his disciples’ feet (John 13:1–20), which symbolizes the ministry of loving service. It is where the concept of a loving friendship with Jesus was introduced, as set forth in John’s Last Supper discourses (John 14—16), and gave the apostles a glimpse into the beautiful prayer life of Jesus, sometimes known as the “high priestly prayer,” recorded in John 17. It is the place where the disciples gathered in fear after the death of Jesus and prayed, with Mary, for the coming of the Holy Spirit (John 20:19–23).
By tradition, this is the same room where Jesus appeared, both before and after the resurrection. It was here that the Risen One made visible his wounds to see and touch, and the room where the faith of Thomas emerged. It is where the Risen Lord breathed on them the Holy Spirit “on the evening of that first day of the week” (John 20:19). It is where tongues of fire appeared to them on Pentecost and “they were all filled with the holy Spirit” (Acts 2:4). That event marks the birthday of the Church in the presence of our Blessed Mother (Acts 1:14). It is from there that the apostles went forth with boldness sharing the Good News. ~
The Upper Room in Jerusalem: The Most Important Room in Christendom
Cenacle (from Latin cēnāculum "dining
room", later spelt coenaculum), also known as the "
Upper Room" (from Koine Greek anagaion and hyperōion, both meaning "
upper room") was the first Christian church. It is a
room in the
David's Tomb Compound in
Jerusalem, and was traditionally held to be the site of the
Last Supper. - Wiki
Ellicott's commentary on Luke 24:53 ~ (53) And were continually in the temple.—The statement is obviously not inconsistent with that in the Acts (
Acts 1:13), that they were abiding in an upper-chamber in Jerusalem. What it indicates is, that their days were spent, not in the routine of common life, but in the prayer of fervent expectation; and for this no place was so fitting as the Temple, which their Master had taught them to look on as in very deed His “Father’s house,” the “house of prayer,” in which the soul of the true worshipper could find access to its God (
Luke 20:46;
John 2:16). There, too, we must remember all the memories of the precious days that had preceded the Passion would be with them in their fullest intensity. We find the same pattern of life presented in
Acts 3:1.
Jamieson-Fausset-Brown Bible Commentary
53. were continually in the temple—that is, every day at the regular hours of prayer till the day of Pentecost.
Gill's Exposition of the Entire Bible
And were continually in the temple,.... At the time of worship, at the hours of prayer, or of public service; and perhaps always privately in an upper room in it, where they, with others, met frequently, and continued, with one accord, in prayer and supplication.