Takes a few hours but you can download the version before sonoma . Just search McMachentosh on safari and go to the first website. after downloading the latest software posted there head to his YouTube and watch his tutorial on how to do all the technical stuff. When everything is done you will be able to use the triple monitor setup 
Thanks for sharing the tutorial with us. 
Downgrade to a previous OS cannot be considered a solution!
Mac OS Sonoma is apple’s formal upgrade and it’s been in beta for 6 months before release… XReal really have to solve this or they should not advertise this feature as working at all. All new Mac will be ship w Sonoma and beyond.
XReal support, pls give us some help and respond here on this topx
Nebula is a fail. I bought Xreal so expensive available in India amazon for using it with mac using 3 screen setup for work. All dreams shattered!
Hi, really sorry for the current issue! I know that the Somoma OS was in beta for several months, but we can only take the standard release version as the reference to develop the software, cuz we didn’t know if there is any change in the formal release.
For the Mac Nebula, we are exploring some solutions to solve the issue, but it takes time to develop and test. Hope you can give us your understanding.