Inconsistent and duplicate drawers on Flutter 2.0.

[SalahAdDin]

Recently, I've tested this package in order tu fulfull my client's requirement on its application.

First, as you can see in the pull request, i updated the library to null-safety. Then, I put it on my project and i folder my custom drawer as follows:

class MainLayout extends HookWidget {
  final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>();

  @override
  Widget build(BuildContext context) {
    Size size = MediaQuery.of(context).size;
    return Scaffold(
      appBar: Header(),
      body: FoldableSidebarBuilder(
        drawer: SideMenu(),
        screenContents: Container(),
        status: FSBStatus.FSB_OPEN,
      ),
    );
  }
}

With my drawer as follows:

class SideMenu extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      child: Drawer(
        child: SafeArea(
          child: Column(
            children: <Widget>[
              SideMenuHeader(
                displayedUserName: 'Luis Alaguna',
              ),
              Expanded(
                  child: ListView(
                padding: EdgeInsets.zero,
                children: <Widget>[
                  ExpansionTile(
                    title: Text("Dashboad"),
                    children: <Widget>[
                      ListTile(
                        leading: Icon(
                          MdiIcons.accountGroupOutline,
                          // size: 40,
                        ),
                        title: Text('Users'),
                        onTap: () {},
                      ),
                      ListTile(
                        leading: Icon(MdiIcons.poll),
                        title: Text('Surveys'),
                        onTap: () {},
                      ),
                      ListTile(
                          leading: Icon(MdiIcons.cogs), title: Text('Setup')),
                    ],
                  ),
                  ExpansionTile(
                    title: Text('Content'),
                    children: <Widget>[
                      ListTile(
                          leading: Icon(MdiIcons.bookInformationVariant),
                          title: Text('Bilgi')),
                      ListTile(
                          leading: Icon(MdiIcons.meditation),
                          title: Text('Tedavi')),
                      ListTile(
                          leading: Icon(MdiIcons.flask),
                          title: Text('Geliştirmeler')),
                      ListTile(
                          leading: Icon(MdiIcons.tooltipTextOutline),
                          title: Text('Hikayeler')),
                    ],
                  ),
                  ListTile(
                    leading: Icon(Icons.settings),
                    title: Text('Ayarlar'),
                  )
                ],
              )),
              SideMenuFooter(),
            ],
          ),
        ),
      ),
    );
  }
}

Well, the problem is the animation has inconsistences and after open the drawer, the drawer is duplicated as half; you can see it on the video.
https://user-images.githubusercontent.com/5034215/114433613-b2c6bc80-9bca-11eb-8ec8-a68098186654.mp4

What's the way to fix this?

Thanks.