We seem to be getting an issue where when we schedule a conference through TMS and check the box to "Include Webex Hybrid Conference," it will create a Webex meeting, but it doesn't include a SIP address in the meeting info and the dialing string it creates in TMS includes letters and numbers before our domain.
We're not really sure why the Webex meeting TMS creates doesn't seem to support SIP dialing because even when we try to manually create the SIP from the meeting number @ domain, it won't dial in. Our Webex accounts all support SIP and don't have any issues aside from this.
If I separately create a Webex meeting and add the SIP from that meeting to add as an external participant in TMS, it dials properly and works. Our TMSXE service is also working if we were to schedule a Webex meeting and include endpoints from Outlook.