enter image description hereenter image description here

When the keyboard comes up, I use the Stack and Positioned to make the button come up as well.
However, when the button comes up over the keyboard, the background becomes transparent and the background is visible, and when it is activated, it becomes opaque again.
I wrote the same as in other files, why is this only on this screen?

      child: Scaffold(
        resizeToAvoidBottomInset: false,
        body: SafeArea(
          child: Stack(
            children: [
              LayoutBuilder(
                builder: (context, constraints) {
                  return SingleChildScrollView(
                    keyboardDismissBehavior:
                    ScrollViewKeyboardDismissBehavior.onDrag,
                    child: ConstrainedBox(
                      constraints: BoxConstraints(minHeight: constraints.maxHeight),
                      child: IntrinsicHeight(
                        child: Column(
                          children: [
                            CustomAppBar(
                              showBack: true,
                              showLogout: false,
                              onBack: () {
                                notifier.prepareExitToRoot();
                                Navigator.of(context).pop();
                              },
                            ),
                      ......
              Positioned(
                left: 0,
                right: 0,
                bottom: 0,
                child: AnimatedPadding(
                  duration: const Duration(milliseconds: 180),
                  curve: Curves.easeOut,
                  padding: EdgeInsets.fromLTRB(20, 0, 20, viewInsetsBottom + 20),
                  child: CustomElevatedButton(
                    onPressed: state.canGoNextInfo ? notifier.nextToPassword : null,
                    child: const Text('다음'),
                  ),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}