Is there coral commonly considered “easy to keep” that you find challenging to keep healthy/alive?

[WAfrican]

Montipora and Acans. Have tons of acropora, torches, zoas, and a chalice that are all thriving but my acan and monti refuses to grow.

 

[Laughterman]

I have challenges with Xenia and Zoa's.

 

[Surskit]

i've tried clove polyps a few times and they've never worked out for me at all

 

[JoJosReef]

Duncans. Always a pitiful performance. Either it stays as one head and eventually closes up or it starts to sprout heads and they all close up at once and just die. Meanwhile, other LPS are getting on just fine.