Some phones under android 9 are quite agressive on background running services. Meaning that they kill services unless you add them on white list.
You can check your mobile settings, maybe do you have some « economy » mode for battery saving, or something like that, which prevent service to run.
I do not have your specific phone to give you the right location of the settings (This website might help you if you do not find it by yourself: https://dontkillmyapp.com/)
After removing it, remove the widget, reboot the mobile, and then place again the widget on screen, to be sure all the services are restored.