First saltwater tank, bta hiding

Hi guys, i hope u can read my poor English.
This is my first saltwater tank. Its a nano fluval edge.
2month since startup and the test is stable. Nitrate is the only thing that wont come under 10ppm.

Any how, in the tank i have 1 clown since week 1-2.
Then i added 1 peppermint ,
1 turbosnail
2dwarf hermits
Feeding 3days apart

I got a small rock with startpolyps

And now my red BTA that i got, and i know my tank is to small but my 200l trigon is on its way.

The problem.
First hour it was opened and bubbly on top of the rock then it whent down between 2rocks but it still opens upp and bubbly, mouth closed. Think i got it to eat a small amont of artemia yesterday.
I spreyed it on the tentakles and it did close up and a few min later it opened again. 3 day now and it is still under the rocks.

Should i be worried or just leave it be?

The clown has come down from time to time to say hi to the nem but there is no room for it.
Thx guys.
Trying to upload a pic so u can se IF its ok or not.