Wow, it sounds like you're doing everything right! If you have really well draining soil and you're getting those temps I would go ahead and water a little more - what size container is the plant in? I live in Texas and when we're approaching the 100's I am watering about every other day - are your leaves showing any sign of drooping? I bet you giving it a break from the sun & maybe giving a little extra water would help. By chance are you able to post a picture?

Thank you will attempt photo. I did water and move to move sun . Could I have a pest

I am thinking same as E. Not enough water to keep the blooms live longer. If I understood correctly its a newly rooted plant and probably does not have the root system quite yet to support growth and blooms so something has to give. You are no doubt in a dry climate so it will be hard (but not impossible) to over water during the summer. I would observe and see how it does in the new location then perhaps start to introduce to higher amounts of sunlight. Or look for afternoon shade locations to place it.

Any thoughts on blooms center browning and dropping

are they staying like that or do they open more? That might be insect damage maybe thrip.

The first blooms 2 weeks ago perfect. Now all like photo, do not open any wider and drop within 1-3 days. Is there a specific way to treat Plumeria for thirps?