This has apparently been an issue for a while, and is a regression.
https://jira.reactos.org/browse/CORE-9057 https://jira.reactos.org/browse/CORE-16043 https://jira.reactos.org/browse/CORE-18227 https://jira.reactos.org/browse/CORE-17818
The latest version I can get to boot is reactos-bootcd-0.4.13-dev-1080-g4843c1a-x86-gcc-lin-dbg.7z available at https://iso.reactos.org/bootcd/reactos-bootcd-0.4.13-dev-108...
The fact that this regression has been dismissed with "Works on my machine!" is deeply troubling. I can't foresee trusting anything to ReactOS.