Arduino BLE with app development

Hi community, I just finished the TinyML courses on edX. I think I learned lots of knowledge and skills about TinyML from the course. Recently, I am trying to connect my Android app with an Arduino device through BLE. I develop my Android app by using the framework Flutter. Everything had been working perfectly in the foreground until I tried to make the connection in the background. I use the flutter_reactive_ble plugin to handle the BLE connection and use the workmanager plugin to handle the periodic task in the background. Does anyone have any related experience? Thank you.