Activity Sensor in Home Assistant App for iOS is Unknown

Tags: #<Tag:0x00007fc3f8bc6290>

I am using Home Assistant Companion App for iOS, and tracking activity sensor for some of my automation. However, recently I found that the activity sensor disapear from the app and its state is now permanently shown as Unknown in HA.

I tried to give the app all the permission I can find in iOS, including Motion & Fitness and Research Sensor & Usage Data enabled. And reinstall the app, but it is still missing.

Did anyone face this issue before? And if can, will you be able to guide me how to fix it? thanks.