import from python to simulink, matlab.eng​ine.Matlab​ExecutionE​rror: Invalid Simulink object name: try11/Constant2.

A very strange error, When I try to run this code in Matlab m code files (action1 and action2 are predefined:

%  action1=1
%  action2=2
set_param('try11/Constant2','Value','action2')
set_param('try11/Constant','Value','action1')
sim('try11.slx')

s1=try11/Constant

no error is reported and the simulation is started. try11 is just a simple Simulink file adding "Constant2" and "Constant". However when I try to run the following in Python.

import matlab.engine
eng = matlab.engine.start_matlab()
eng.workspace['action2'] = matlab.double([0.0])
eng.workspace['action1'] = matlab.double([1.0])
eng.tryy(nargout=0)
reward = eng.eval('ans.output')
print(reward)

I get the following error in python Console:

Error using tryy (line 3)
Invalid Simulink object name: try11/Constant2.
Caused by:
    Error using tryy (line 3)
    The block diagram 'try11' is not loaded.
Traceback (most recent call last):
  File "/home/majid/anaconda3/lib/python3.8/site-packages/IPython/core/interactiveshell.py", line 3343, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-2-06fc4fb2fc97>", line 1, in <module>
    runfile('/home/majid/PycharmProjects/reinforcementlearning/Main_Directory/mattry.py', wdir='/home/majid/PycharmProjects/reinforcementlearning/Main_Directory')
  File "/snap/pycharm-professional/218/plugins/python/helpers/pydev/_pydev_bundle/pydev_umd.py", line 197, in runfile
    pydev_imports.execfile(filename, global_vars, local_vars)  # execute the script
  File "/snap/pycharm-professional/218/plugins/python/helpers/pydev/_pydev_imps/_pydev_execfile.py", line 18, in execfile
    exec(compile(contents+"\n", file, 'exec'), glob, loc)
  File "/home/majid/PycharmProjects/reinforcementlearning/Main_Directory/mattry.py", line 13, in <module>
    eng.tryy(nargout=0)
  File "/home/majid/anaconda3/lib/python3.8/site-packages/matlab/engine/matlabengine.py", line 70, in __call__
    return FutureResult(self._engine(), future, nargs, _stdout,
  File "/home/majid/anaconda3/lib/python3.8/site-packages/matlab/engine/futureresult.py", line 67, in result
    return self.__future.result(timeout)
  File "/home/majid/anaconda3/lib/python3.8/site-packages/matlab/engine/fevalfuture.py", line 82, in result
    self._result = pythonengine.getFEvalResult(self._future,self._nargout, None, out=self._out, err=self._err)
matlab.engine.MatlabExecutionError: Invalid Simulink object name: try11/Constant2.