“The church in Corinth was composed of probably MOSTLY gentiles”
Corinth had a large population of Jews.
“Christianity “ was/is a sect of 2nd temple Judaism.
Corinth may have had a large Jewish population but the early Christian church didn't seem to have a large Jewish population.
Col 4:10 Aristarchus my fellow prisoner greets you, with Mark the cousin of Barnabas (about whom you received instructions: if he comes to you, welcome him),
Col 4:11 and Jesus who is called Justus. These are my only fellow workers for the kingdom of God who are of the circumcision; they have proved to be a comfort to me.
Granted this was Colossae but it is likely representative. Jewish people for the most part were intimidated by those who gave them pressure to leave the way.