Hey there Vinavanshal,
Thanks for reaching out to the Apple Support Communities.
To get started, if you disable Low Power Mode are you able to enable/disable cellular data from the Control Center? When Low Power Mode is on, it may cause some features and settings not to work, and some tasks may take longer to complete.
Check out this link for more details: Use Low Power Mode to save battery life on your iPhone or iPad - Apple Support
When Low Power Mode is on, your iPhone or iPad will last longer before you need to charge it, but some features might take longer to update or complete. Also, some tasks might not work until you turn off Low Power Mode, or until you charge your iPhone or iPad to 80% or higher.
Low Power Mode reduces or affects these features:
* 5G (except for video streaming) on iPhone 12 and iPhone 13 models1
* Auto-Lock (defaults to 30 seconds)
* Display brightness
* Display refresh rate (limited up to 60 Hz) on iPhone and iPad models with ProMotion display2
* Some visual effects
* iCloud Photos (temporarily paused)
* Automatic downloads
* Email fetch
* Background app refresh
If the issue persists with Low Power Mode disabled, we'd also recommend to try restarting your iPhone with the steps in this next link here: Restart your iPhone - Apple Support
While restarting may seem like a simple step, it can often help with resolving some unexpected issues like this.
Keep us updated on the results.
Take care.