ClustalO with multithreading parameter threads appear sleeping

Hello folks,

I am running clustalo with threads flag, at the begining clustalo was using the number of threads I specified but when I checked it next day, all of the threads seem sleeping except one. Do you think thats normal, or am I missing something somewhere?

Here is the code I used

clustalo --in SGFiltered_NR --out SGFilteredAligned --threads=40

and here is the picture of the htop