AdGuard cuts off network connection to Custom DNS on iOS

### Please answer the following questions for yourself before submitting an issue

- [X] Filters were updated before reproducing an issue
- [X] I checked the [knowledge base](https://adguard.com/kb/) and found no answer
- [X] I checked to make sure that this issue has not already been filed

### AdGuard version

4.5.2

### Environment

- OS: 17.3.1
- Device: iPhone 17 plus

### Ad Blocking

_No response_

### Privacy

_No response_

### Social

_No response_

### Annoyances

_No response_

### Security

_No response_

### Other

_No response_

### Language-specific

_No response_

### Advanced protection for Safari

- [X] yes, I do

### Which DNS server do you use?

Custom DNS

### DNS protocol

DNS-over-QUIC

### Custom DNS

AdGuard Private DNS

### DNS filtering

- [X] yes, I do

### Custom DNS filter

Na

### DNS implementation

AdGuard

### Tunnel mode

Split-Tunnel

### Low-level settings

Bootstrap server:
Fallback server:
Blocking mode, etc:

### Issue Details

Steps to reproduce:
1. Have AdGuard Ablocker for IOS & AdGuard VPN for IOS enabled.
2. After so often the connection to private DNS cuts off and cuts of Network connection.
3. To get it working have to a least disable VPN and toggle wifi off the on again to refresh the connection.

### Expected Behavior

Should not cut off connection to network

### Actual Behavior

Network gets cut off.

### Screenshots

_No response_

### Additional Information

I will send the logs for this report.