VirtualBox screen auto-resize does not work in ReactOS since VirtualBox 6.1.0

After installing VirtualBox 6.1.x guest additions in ReactOS, the auto-resize feature does not work and the option for it remains grayed out. In VirtualBox 6.0.20 that feature still works in ReactOS. On Windows 2003, auto-resize works in both VirtualBox 6.0.x and 6.1.x (ReactOS logs were captured from VirtualBox 6.1.0 and 6.0.20). Both Win2003 and ReactOS VMs have the same configuration.