Question: Is RootFinding[Isolate] thread safe?

Hi!

I have a problem recently with running RootFinding:-Isolate inside a procedure which is run on threads. I have many polynomial systems to treat so I would like to balance computations between cores. Unfortunately, my code always breaks computation kernel with the error:

java.lang.NullPointerException

at com.maplesoft.mathdoc.model.WmiModelLock.acquireLock(Unknown Source)
at com.maplesoft.mathdoc.model.WmiModelLock.writeLock(Unknown Source)
at com.maplesoft.worksheet.connection.WmiOutputUpdateBuffer$UpdateSynchronizer.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

I wrote a small example below

f:=proc(n)

   local i;

   for i from 1 to n do
    try

      RootFinding:-Isolate([a^2+b^2-1/3c^2,a^2-1/3b^2+c^2-1/3,a^2-1/3b^2-1/3c^2+1],[a,b,c]):

   catch "":
     next:
   end try:
  end do:
end proc:

Threads:-Task:-Start ( null, Task[f,10000], Task[f,10000], Task[f,10000]);

I have no much of experiences with threads in Maple so I would not be surprise if I'm trying to do something completely wrong here. Any hint or advice will be appreciate.