There’s no need to explain Acts, because it’s so clear that Paul didn’t travel from city to city to attend the synagogues of the Jews just to fill a pew, but to preach to them that Jesus is their Messiah, and he had to be there when they were there to hear him, which was on the sabbath.
Just as circumcision was physical in the old covenant, but spiritual in the new, the rest for Israel was physical in the old covenant, but spiritual in the new.
Jesus is our rest 24 7 in the new covenant, Matthew 11:28-29, so now our rest, which is what sabbath means, is no longer on a ceremonial day, but is found in Jesus.
Scripture says the sabbath was just a shadow of Jesus, who is the substance.
Col 2:16 Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the sabbath days:
Col 2:17 Which are a shadow of things to come; but the body is of Christ.
Note also that the two love commands which superseded the old ten, have no required day to keep at all, leaving us free to assemble together on any day we want - the apostles chose the Lords day, the first day of the week, since He rose on that day.
Shalom Aleichem