But as you can see they “broke bread” daily. Not just on the first day of the week. They were simply eating.
My opinion, there's a bit more evidence that it refers to communion.
One example
Matthew 26: 26. As they were eating, Jesus took bread, gave thanks for it, and broke it. He gave to the disciples, and said, "Take, eat; this is my body."
He took bread, and broke it. He broke bread.
Yes, the book of Acts talks about the apostles breaking bread daily. That's why those groups which trace an unbroken practice back to the time of the apostles (I'm thinking here of Catholic and Orthodox churches) celebrate communion daily.
My impression from the New testament is that the early Church gentiles tended to meet on the first day of the week for communion, worship, fellowship.