Hey there Nouraz1234,
Thanks for reaching out to the Apple Support Communities.
To get started, do recall if your iPhone had Find My Network enabled in Settings > [Your Name] > Find My > Find My iPhone before the device went missing? If so, this setting would allow your iPhone to still be seen and tracked if offline, in power reserve mode, or when powered off. So this may be why you received a notification that the iPhone was recently seen, but Lost Mode is still showing pending in the Find My settings, since your iPhone would need to be powered on and connected to a network before Lost Mode is activated.
For more details on Find My Network, and what to do if you're unable to locate your device, check out the following resource under the "Locate it on a map" section: Use the Find My app to locate a missing device or item - Apple Support
Locate it on a map
1. Open the Find My app.
2. Choose the Devices or Items tab.
3. Select the device or item to locate it on the map. If you belong to a Family Sharing group, you can locate the devices in your group.
4. Choose Directions to open its location in Maps.
If you turn on Find My network, you can locate your device or item even if it's not connected to a Wi-Fi or cellular network. The Find My network is an encrypted anonymous network of hundreds of millions of Apple devices that can help you locate your device or item.
Can't locate your device?
* You might not have Find My turned on.
* If you're using the Find My app, you can't see your device's location if more than seven days have passed since its last location was sent to Apple.
* If you're using iCloud.com/find, you can't see your device's location if it's powered off, the battery has run out, or more than 24 hours has passed since its last location was sent to Apple.
* Learn how you can still protect your information.
We hope that's able to help.
Take care!
