Find My not locating iPad or going into lost mode

left iPad in back of uber, when checked Find My the location was my home where the uber had left me, however the apple pencil said was located at job, both locations were in correct.

I placed iPad into lost mode from my iPhone, also attempted to play a sound and it said the iPad was offline (iPad has cellular connection)

fortunately retrieved iPad from uber however when i did the iPad was fully charged, connected to xfinity mobile wifi,and cellular data. but not only was the location still not updating ,it wasn't in lost mode.

it did however go lost mode and update the location after turn on the screen and unlocked the iPad,

so my is question is why isnt my iPad connected properly to my find my