Toadstool leather coral not standing up?

[randomfishdude]

Hello,
So my toadstool leather coral that I got about a month and a half ago has never stood up. The most it's ever stood up was a few times in the evening about 1/2 inch.The little polyps do come out though.
I don't really know why every other coral is thriving and growing.

 

[Stephen Glover]

Looks like it doesn’t have a stem. Dont worry, if it’s happy it will grow one.