iMessage / FaceTime & other Apple ecosystem features only work with VPN enabled

Hi everyone,

I've recently stumbled upon this issue on my year-old hackintosh (running MacOS Sonoma 14.6) where services like iMessage & FaceTime don't work unless I have a VPN enabled. Apple store works just fine.
This doesn't seem like an issue with my home's public IP being banned as it also happens outside my home.

I've tested with a VPN provider (Wireguard) & my own servers using both Wireguard and OpenVPN and achieve the same results: iMessage messages go through, my iPhone (iOS 17.6) DND syncs with my hackintosh, and I also get the calls and SMS messages from my iPhone on macOS.

I've also noticed a weird behaviour with Handoff: It only works one-way, from my iPhone to the hackintosh, not the other way around. I can copy files/text from my phone and paste it on my hackintosh and get open safari tabs on mac as well WITHOUT VPN. Other way around still doesn't work with VPN on.

I'm using the latest itlwm kext (AirportItlwm_v2.3.0_stable_Sonoma14.4.kext.zip), on a Dell latitude 7400 laptop.

I'm not sure when this issue started to happen, but it could possibly be when I first upgraded from Ventura to Sonoma a few months back. I can recall that it was working fine (without VPN) after following Dortania's guide.
As I previously mentioned, I have genuine devices linked to my iCloud account, such as an iPhone 13, AirPods Pro Gen 2 and an Apple watch SE from 2023.

Please let me know if there's more info I can provide, I'll be more than happy to provide it and get this issue fixed. Also, escuse me for any noob behaviour. Thanks in advance for your time!