FlutterFlow / Flutter - type '_Map<Object?, Object?>' is not a subtype of type 'Map<String, dynamic>'

Question

I get this error when running the app on a real device. Testing the web version does not give the error. The data that is submitted is in JSON format and is valid as a format.

error:

type '_Map<Object?, Object?>' is not a subtype of type

'Map<String, dynamic>' in type cast See also: https://flutter.dev/ docs/testing/errors

enter image description here

// Automatic FlutterFlow imports
import '/backend/backend.dart';
import '/backend/schema/structs/index.dart';
import '/flutter_flow/flutter_flow_theme.dart';
import '/flutter_flow/flutter_flow_util.dart';
import '/custom_code/widgets/index.dart'; // Imports other custom widgets
import '/flutter_flow/custom_functions.dart'; // Imports custom functions
import 'package:flutter/material.dart';
// Begin custom widget code
// DO NOT REMOVE OR MODIFY THE CODE ABOVE!

import 'package:calendar_date_picker2/calendar_date_picker2.dart';
import 'dart:convert'; // Import for json decode

final today = DateUtils.dateOnly(DateTime.now());

class DatePickerWidget extends StatefulWidget {
  const DatePickerWidget({
    super.key,
    this.width,
    this.height,
    required this.rebuildpage,
    required this.backAction,
    required this.jsonn,
    this.colorblockDates,
    this.colorownerDate,
    this.coloradminDate,
    this.colorwaitingDate,
  });

  final double? width;
  final double? height;
  final Future Function() rebuildpage;
  final Future Function() backAction;
  final dynamic jsonn;
  final Color? colorblockDates;
  final Color? colorownerDate;
  final Color? coloradminDate;
  final Color? colorwaitingDate;

  @override
  _DatePickerWidgetState createState() => _DatePickerWidgetState();
}

class _DatePickerWidgetState extends State<DatePickerWidget> {
  // List<DateTime?> _selectedDates = [DateTime.now()];
  List<DateTime?> _selectedDates = [];

  List<DateTime> blockDates = [];
  List<DateTime> ownerDates = [];
  List<DateTime> adminDates = [];
  List<DateTime> waitingDate = [];

  @override
  void initState() {
    super.initState();
    _parseDatesFromJson();
  }

  void _parseDatesFromJson() {
    final jsonMap = widget.jsonn as Map<String, dynamic>;
    final List<dynamic> data = jsonMap['data'];
    for (var item in data) {
      final date = DateTime.parse(item['iso_date']);
      final status = item['status'];
      switch (status) {
        case 'block':
          blockDates.add(date);
          break;
        case 'owner':
          ownerDates.add(date);
          break;
        case 'reception':
          adminDates.add(date);
          break;
        case 'waiting':
          waitingDate.add(date);
      }
    }
  }


  Map<Object?, Object?> objMap = { 'key1': 'value1', 'key2': 5 };
Map<String, dynamic> strDynamicMap = Map<String, dynamic>.from(objMap as Map);

  TextStyle? _dayTextStyle(DateTime date) {
    if (blockDates.any((blockDate) => date.isAtSameMomentAs(blockDate))) {
      return TextStyle(
          color: widget.colorblockDates ?? Color.fromARGB(255, 50, 49, 49),
          fontWeight: FontWeight.bold);
    } else if (ownerDates
        .any((ownerDate) => date.isAtSameMomentAs(ownerDate))) {
      return TextStyle(
          color: widget.colorownerDate ?? Color.fromARGB(255, 4, 101, 246),
          fontWeight: FontWeight.bold);
    } else if (adminDates
        .any((adminDate) => date.isAtSameMomentAs(adminDate))) {
      return TextStyle(
          color: widget.coloradminDate ?? Color.fromARGB(255, 10, 123, 34),
          fontWeight: FontWeight.bold);
    } else if (waitingDate
        .any((waitingDate) => date.isAtSameMomentAs(waitingDate))) {
      return TextStyle(
          color: widget.colorwaitingDate ?? Color.fromARGB(255, 10, 123, 34),
          fontWeight: FontWeight.bold);
    }
    return null;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: CalendarDatePicker2WithActionButtons(
          config: CalendarDatePicker2WithActionButtonsConfig(
            calendarType: CalendarDatePicker2Type.range,
            disableModePicker: true,
            dayTextStylePredicate: ({required DateTime date}) {
              return _dayTextStyle(date);
            },
          ),
          value: _selectedDates,
          onValueChanged: (dates) async {
            if (dates.length == 2 && dates[0] != null && dates[1] != null) {
              final start = dates[0]!;
              final end = dates[1]!;
              //  final end = dates[1]!.add(Duration(
              //     days: 1)); // Add one day to include the end date in the range

              FFAppState().value1 = start;
              FFAppState().value2 = end;

              // Check if the selected range includes any block dates
              bool includesBlockedDates = blockDates
                  .any((date) => date.isAfter(start) && date.isBefore(end));

              if (includesBlockedDates) {
                // Show dialog if the range includes block dates
                showDialog(
                  context: context,
                  builder: (BuildContext context) {
                    return AlertDialog(
                      title: Text("Грешка при избор на период"),
                      content: Text(
                          "Избраният от вас интервал включва вече резервирани дни. Моля изберете друг интервал или направете две отделни резервации."),
                      actions: <Widget>[
                        TextButton(
                          child: Text("Добре"),
                          onPressed: () {
                            Navigator.of(context).pop();
                          },
                        ),
                      ],
                    );
                  },
                );
              } else {
                setState(() {
                  _selectedDates = dates;
                });
                await widget.rebuildpage();
              }
            }
          },
          onOkTapped: () async {
            await widget.backAction();
          },
          onCancelTapped: () async {
            await widget.backAction();
          },
        ),
      ),
    );
  }
}

The widget should display a calendar with blocked and colored dates.

Testing the flutterflow virtual simulator also had no problems.The error only appears on Android and iOS devices