Unable to Send Messages via ANY XBOX Platform/App

I've recently bought an Xbox One X, but to give a bit of a background we used to own an Xbox One S which I sold in 2019 which did not have this issue.

From the first time I set it up 2 weeks ago, I've found that I'm unable to send messages on my console as it gives me an error regarding Privacy settings, even though every option is set to 'Allow'. I have tried two Xbox Phone Apps (both Android and iOS),
the Windows 10 Xbox App (Win Key + G) and the Xbox.com on 3 different comnputers, and none allow me to send any messages. I'm now at the stage where I'm about to tear my hair out as I've tried everything to no avail. In order to help you guys, I'll give as
much detail as I can on everything I've tried so far.

I have narrowed it down to some sort of issue with my account rather than any of the devices, since my wife's account is signed in on the same devices and can send messages without issue. On my account however, whever I try and send a message to anyone
I get the following errors dependant on the device:

On Xbox.com:
"Error. An unexpected error occured. Please try again later"
No error specifics attached, just the above message.

Windows Xbox and Xbox Phone Apps (Android + iOS):
"Access to feature blocked. You are unable to access this feature because of how your account is set up. You can change this by modifying your privacy settings on Xbox.com".
I followed the instructions and went to Xbox.com but when I checked my privacy settings, all options are set on 'Allowed' on all 3 tabs, and nothing is set as blocked/friend's only. Signing into my wife's profile on the app does not give any errors,
and I can send messages as normal.

On the Xbox One Console:
"To do this, change a setting. You cannot send messages because of how your account is set up. To change this, customise your XBOX Live privacy settings in Settings > Account > Privacy & Online Safety."
Again, checking the settings on the console itself I can see everything is set to 'Allowed' and mirror what I had set on the website and still no change. I even went on to message settings and set everything to unrestricted rather than mature/blocked and
still no change. Also, clicking on "Got something to Share?" on the community tab gives the same error. To reconfirm, my wife's account on the same Xbox can send messages as normal, even though her privacy settings are more private than mine currently
are.

Xbox One playing a X360 game:
"Voice and text communication is blocked for this profile. To change your privacy & online settings, go to Settings, Privacy"
I pressed Start+Back to get the X360 Guide to appear and then clicked on 'Chat' to get this error. This above is somethhing I cannot do, as there is no 'Privacy' option in settings on the BC menu by design, only on the original 360. If I go on a friend's
profile, the option to send a message is completely greyed out, as is the option to 'Create New' when I open Messages. I didn't try my wife's profile this time, as I have already established it's not the device with the issue.

However, on an actual Xbox 360 console:
Luckily I have one still in the attic. Strangly, messages can be sent to anyone as normal and once sent, they all show up on the conversation list on my Xbox One/Xbox App(etc)... but trying to continue the conversation on these platforms gives the same
errors above and I'm back to square one. I've read the profiles on X360s are different to on an XBONE even if it's the same account, so this doesn't really tell me much other than there's an issue with the XBONE/Win10 version of my profile.

I have been reading in depth about similar issues for the last two weeks and have
tried everything to resolve it and none of the below have worked or made any difference... but for clarirty I've:

- Spoke to Microsoft Tech Support who told me power cycle my devices, and to check privacy settings. When that didn't work they advised to post here instead. Said they don't offer phone/chat support for this problem.

- Tried http://support.xbox.com/fix-messaging - re-confirmed my mobile number via the link on that page (http://account.live.com/reputationcheck).

- Tried https://enforcement.xbox.com/en-US and can see my account is in 'Perfect Record'.

- Removed my account from all of the above devices, restarted, and redownloaded the profile/signed back in depending on the device.

- Changed my Microsoft Account password, Added/Removed 2FA (tested both states) and logged in with new password for each device.

- Checked location settings match where I live.

- Uninstalled Phone app on both my Android and my wife's iPhone and reinstalled them.

- Factory reset my Xbox One X and re-downloaded profile.

- Removed Pass-key from Xbox One profile.

- Changed an option within Windows 10 so that 'Microsoft Services' is allowed to access information from my Microsoft account. A bit of a weird one this, but it was a suggestion on here and I was out of options.

- Signed my profile in to a friend's Xbox to rule out my new Xbox having a fault - still can't send any messages but he can on his.
- Set everything to 'Blocked' on the Xbox.com website, waited 24 hours and then set everything back to 'Allowed' to try and force a reset. No change another 24 hours later.

As you can see, I've tried everything to fix this issue before asking for help here and I'm hoping it's something simple that I've overlooked. I went in to detail on what I had tried not only to hopefully help you guys narrow it down, but to avoid being
asked to try things I have already done. I'm at my wit's end with this and I haven't found any sort of solution in two weeks. If anyone can assist me, I would be extremely appriciative.

Thank you in advance.

:)