We don't see any symptoms of disease or signs of a pest. Is the plant grown outside during the warmer months (about May through October)? If not, and if you have that option, that may help it remain vigorous and tolerant of more challenging conditions during the winter. Houseplants often struggle over the long term, if they're always indoors, with dry (low-humidity) indoor air, reduced air circulation, and inadequate light, though the latter will certainly depend on how much window light they receive. (In front of a sunny window would be ideal for any of the jasmine species.) Has the plant been repotted into fresh potting mix in the past year or two? If not, it might be due for a repotting, and now is a good time of year to do that since it's entering a more active growth phase for the spring/summer.

Miri