Party and Game invititations aren't coming through on any device

Just recently my Game and Party invitations have stopped coming through to any of my devices. This includes my Xbox One console, my Windows 10 PC and my Android device.

I have tried numerous things in order to make them work again but to no real success. My console has been hard reset several times now, I've cleared the cache unplugging it. I've taken myself out of the insider ring, and even reset my console twice. A few
searches also took me to clearing the Blu Ray persistant storage, again which had no impact.

I have played around with notification settings on my Xbox One, turning them all off, removing my profile, resetting my device and adding it again, which also yielded no results.

The settings for notifications are all set to be on, and notifications for achievements still show on my console, as well as messages, screenshots etc, it is just Party and Game which fail to show up at all.

I have also made sure that my profile is set to online on my console.

With regards to my other devices, my Android device usually acts like it is possessed when I'm not at my console, with numerous party invites appearing, which stopped at the same time my Xbox Party and Game invites stopped working. To make sure it wasn't
a problem with my Wi-Fi, I also tested it on mobile data which had the same results.

For my Windows 10 PC, i have added and removed the Xbox Companion app several times now, with added computer restarts for good measure. I have also gone into advanced app settings to Terminate and Reset the Xbox Companion App, Game Bar and Xbox Live apps
on there for good measure.

My Xbox is set up as a console on the network, and I've made sure all port forwarding rules are in place, even though it has had an Open NAT type from day one. The console also has its own static IP address, but nothing has changed on my network and the
invites used to show up before.

Since then, I've removed the Xbox Apps on my PC and Android device, leaving solely my Xbox. Notifications for Party and Game do not show up, and I'm running out of ideas on how to fix this after hours spent attempting different solutions and searching through
Reddit and Google. I can join parties and send invites, but this isn't so helpful when some of my friends are hiding offline and are in invite only sessions.

All help is greatly appreciated.

:)