Q.Plumerias
I have a Plumeria with a bud stem that I have been watching to open for a few days now and yesterday it started drooping and really bad today . Live in North East Texas and is very warm , have two large white ones and they never did this ….could it be to much water and if it dries out will the stem straighten up again ?

These plants needed well draining soil.
Check the soil to make sure it is not soggy. Pull back any mulch to aid in the soil drying if it is too wet.
https://www.gardeningknowhow.com/ornamental/flowers/plumeria/plumeria-flowers-dropping.htm
https://www.gardeningknowhow.com/ornamental/flowers/plumeria/growing-plumeria.htm