Complex sentence: Although they had established a cult following, the group had not found much mainstream popularity across the United States; however they did have some success in the UK and charted at number 15 on the Billboard Hot Dance Club Play.
Split into simpler sentences: Although they had established a cult following, the group had not found much mainstream popularity across the United States. However, they did have some success in the UK and charted at number 15 on the Billboard Hot Dance Club Play.