Microsoft PSTN Conferencing, Outlook Meeting Invite PSTN Number not in E.164

For some reason if you have Microsoft PSTN Conferencing (where Microsoft are your carrier for PSTN conferencing on Skype for Business Online / Cloud PBX), the main PSTN number in your Outlook invite it not formatted in E.164 (missing the “+” on both the test and the link).

This is a known issue/bug, hopefully it will be fixed sometime soon