I also thought them to be two different plants till I found both types of branches on the same tree. Variegated cultivars have cytoplasmic inheritance and it is common to see a green branch appearing on a variegated tree/shrub, and f left unattended, the whole plant may turn green.
P. tobira from the same tree
First photograph normal green branch with narrow thicker leaves
Second photograph branch with variegated and broader leaves
Third photograph Both types of branches on same plant