Given the class

classdef bad_class
  methods (Access = 'private')
    function foo1(obj)
      disp ('call foo1');
    end
    function foo2(obj)
      disp ('call foo2');
      clear all;
      obj = evalin ('caller', 'obj');
      disp ('     clear all');
      obj.foo1 ();
    end
  end
  methods
    function foo3(obj)
      obj.foo2();
    end
  end
end

In member function `foo2` the command `clear all` clears all variables in the current scope.  This is conform with Matlab R2021a.

In Matlab one can recover the lost variable as described in `foo2`.  In Octave 6.4.0, 7, and 8 the output is:

call foo2
     clear all
error: subsref: method 'foo1' has private access and cannot be run in this context
error: called from
    foo2 at line 11 column 7
    foo3 at line 16 column 7

A workaround is declaring everything as "public".  Same problem with "protected"

Similar to bug #56953.