From personal experience crentch,when i tried led too,my acros needed a couple of months-if not more- to get use to led lighting.
Especially when i took corals from t5's.
Is it close to the light fixture?What's the distance?
Even with other types of light,some acros need some time to adjust.
Maybe it just needs some time.
The polyp extension isn't bad,so that is a good sign.