Q.Jasmine plant questions
I brought it in on the first sign of cold temps, then they went back up and probably won’t drop until end of Oct. Did I bring in too soon? Also, leaves are turning bright red, then die and fall off…why?
When the light falling on a plant changes suddenly, it causes a massive upheaval in the plants' systems. They try to get rid of as many leaves as possible to compensate for the reduction in energy, etc. That's why the best practice is to accustom plants to light changes slowly. We call that acclimating them. Here's an article that will help you do that without such a shock to your plants. https://www.gardeningknowhow.com/houseplants/hpgen/acclimate-plants-indoors-winter.htm
PS you can take your plant back outside now, then continue with the acclimating process.