Severe battery drain while idle

### Issue Details

This is likely the same issue as #1831. I don't know when it started, but my battery has been, for the past months, draining at least 30% overnight while the phone is idle/stand by. I disabled all apps' "Background data refresh", and the phone is always on strong signal Wi-Fi. I looked at the DNS logs first thing this morning and noticed that the same few reverse IP lookups are performed literally every 30 seconds, non-stop, forever. The IPs in question are all private IPs that do not exist on my Wi-Fi network.

Do you have any idea what could be causing this?

Thanks

### Screenshot

### Details
- **AdGuard version:**
- AdGuard for iOS 4.3.1(919)
- **Device model and storage size:**
- iPhone 12 128GB
- **Operating system and version:**
- iOS 15.2