Unable to get silent push notification in background, when applications takes Location in background Silent Push Notifications works fine but when I stopUpdating location in background then some time Silent notifications are delivered and some time doesn't.
Silent push notification not always delivered when application is background mode
content-available (aka "background" or "silent") push notifications are throttled when being delivered to apps that are in the background. Background push notifications are never guaranteed to be delivered to the app every single time.
The WWDC 2020 video "Background execution demystified" (https://developer.apple.com/videos/play/wwdc2020/10063/) explains the factors that effect background runtime.
I suggest looking into using a notification service extension as discussed at https://developer.apple.com/documentation/usernotifications/unnotificationserviceextension. The Notification Service Extension will be executed for every visible push notification. So, it could serve your needs, as long as the user has not disabled the visibility of your notifications through various settings. The service extension will not be executed for push notifications that will not be presented visually.