The previous beta for Dragon Ball FighterZ had some issues when trying to matchmake on PS4 (especially over the weekend), but that was fixed with the extended test earlier this week. However, those issues remained on Xbox One, where it was deemed virtually impossible to fight on the game servers.
As a compensation and a last-ditch effort to fix things ahead of launch on the day after tomorrow, the publisher announced a new extended beta phase, of just 24 hours, exclusively dedicated to Xbox One owners. Thus, starting today (Jan 24) 5:00 AM GMT, and until 5:00 AM GMT tomorrow (Jan 25), will be able to test out the matchmaking on Xbox One. Bandai Namco had this to say on their Twitter:
"Hi FighterZ! We've made the necessary improvements in order to enable X1 users to experience DRAGON BALL FighterZ in all of its online multiplayer glory; join us for an Xbox One exclusive open beta at the following dates/times - Start: Jan. 23 at 9pm PST / End: Jan. 24 at 9pm PST"