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.