That looks like it should work. Just a couple of thoughts: The default gateway is irrelevant. That’s only where the OS sends packets that don’t match the netmask. Since these addresses all lie within the same /24 range, the default gateway will never be used. It wouldn’t hurt to check the ARP tables of each OS to see whether the VM MACs ever show up on the remote host or VM. Are the two hosts connected with a cable, or via WiFi? If the latter, VirtualBox has to do some software trickery to make bridging work, and I can imagine that perhaps some WiFi devices wouldn’t play nice.
That looks like it should work. Just a couple of thoughts: The default gateway is irrelevant. That’s only where the OS sends packets that don’t match the netmask. Since these addresses all lie within the same /24 range, the default gateway will never be used. It wouldn’t hurt to check the ARP tables of each OS to see whether the VM MACs ever show up on the remote host or VM. Are the two hosts connected with a cable, or via WiFi? If the latter, VirtualBox has to do some software trickery to make bridging work, and I can imagine that perhaps some WiFi devices wouldn’t play nice.