Each Xcode beta version corresponds to a specific Vision OS runtime beta version; otherwise, it won't run. For example, if you're using Xcode 15 beta 8, the compatible Vision OS runtime version is Vision OS runtime beta 3. Apple won't allow you to install Vision OS runtime beta 4 on Xcode 15 beta 8. I suspect you may be installing Vision OS runtime through the command line, inadvertently bypassing this Apple restriction.
You need to install the latest Xcode beta or install the older Vision OS runtime beta 3.
I'm not 100% sure but I hope this may help.
Kada_ant
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