good day bosses, i have tried all that was written above but did not work so what solved it for me was the scrollControlDisabledMaxHeightRatio parameter of the showModalBottomSheet function. its set to 9/16 by default, I then change it to 8/10, like this:

            showModalBottomSheet(
                        scrollControlDisabledMaxHeightRatio: 8 / 10,
                        enableDrag: false,
                        context: context,
                        builder: (context) => SingleChildScrollView(
                            child: Padding(
                          padding: EdgeInsets.only(
                            bottom:MediaQuery.of(context).viewInsets.bottom),
                          child: YourWidget(),
                        )),
                      );