Issue with Bluetooth Background Scanning on iOS 15.7.3. BLE. Swift

Question

I'm facing an issue with background scanning of Bluetooth on devices with iOS 15.7.3. I'm developing an application that needs to discover BLE devices even in the background mode. However, the didDiscover method is not getting called during background scanning.

Here's what I've already checked and configured in my project:

• Appropriate permissions for Bluetooth usage and background processing are in place.
• Flags in the project settings for background processing are configured correctly.
• I've verified that BLE devices are set up for advertising in the background.
• There are no physical obstacles or interference; devices and BLE devices are in an open environment.

Additional details and conditions:

• The application initiates background scanning in the applicationDidEnterBackground method.
• At the beginning of the test, the BLE device is not accessible. I bring it near the iPhone after approximately 5 minutes of the app being in the background.
• If I don't move the BLE device away from the iPhone, it is detected almost immediately after the app goes into the background, but only once.
• The phone screen doesn't lock during the test.
• The CBCentralManagerOptionRestoreIdentifierKey option is used in the CBCentralManager.
• On an iPhone 12 mini with iOS 16.3.1, background scanning works, but the device is found only once for call scanForPeripherals method.
• The following filters are used: CBUUID(string: "330C5AD1-7261-4F06-B87C-0F6342365C2E") and CBUUID(string: "4c6607e0-2c3d-4fca-b201-0246773d6e9c").
• If during the test you go to the Bluetooth settings of the iPhone (where there is a search for devices), the didDiscover method begins to report found devices
• Advertisement data for BLE looks like this

7 elements
0 : 2 elements
key : "kCBAdvDataServiceUUIDs"
value : 1 element
0 : 4C6607E0-2C3D-4FCA-B201-0246773D6E9C
1 : 2 elements
key : "kCBAdvDataRxSecondaryPHY"
value : 0
2 : 2 elements
key : "kCBAdvDataTimestamp"
value : 719149435.0168051
3 : 2 elements
key : "kCBAdvDataLocalName"
value : GB3_0CCE
4 : 2 elements
key : "kCBAdvDataRxPrimaryPHY"
value : 0
5 : 2 elements
key : "kCBAdvDataServiceData"
value : 1 element
0 : 2 elements
key : 330C5AD1-7261-4F06-B87C-0F6342365C2E
value : \<01020304\>
6 : 2 elements
key : "kCBAdvDataIsConnectable"
value : 1

Here is a link to the repository with the test application. This is a test application that I use for testing. The repository contains code that is not needed for testing. The required classes for testing are AppConfiguration, BackgroundScanManager, and BackgroundBLEManager.

After bringing the BLE device near the iPhone, I wait for approximately 15-20 minutes.

Please, help me understand why the didDiscover method is not being called in the background mode on iOS 15.7.3. Perhaps someone has encountered a similar problem and can provide advice or recommendations?

About feature

We have a BLE device that can generate notifications. We can receive these notifications after connecting to the device during synchronization or from advertising data where the device embeds flags that allow us to determine which notifications have appeared on the device. When the device generates a notification, it starts advertising a service with the identifier 330C5AD1-7261-4F06-B87C-0F6342365C2E. In a real application (not a test one), we initiate background scanning with a filter for 330C5AD1-7261-4F06-B87C-0F6342365C2E. The use case looks like this:

1. The user minimizes the application (applicationDidEnterBackground), and we start background scanning.
2. After 5 minutes, if we were connected, we disconnect from the device.
3. When the device generates a notification, we find it during the background scan, extract the notifications from the advertising data, and connect to the device if necessary. However, as I mentioned before, the background scanning does not find the device.

Thank you very much!

I have tried different ways to solve this problem, but none works