Subsites missing after adding to add-on domains

Hi There,

I set-up several subsites to be mapped to various domains and since doing so 2 (out of 5 sites) have disappeared and now present a 404 error message.

Here is one such example of one that isn't working:

http://phoenixhotel.hakubahotel.group

Here is one that is:

http://springshotel.hakubahotel.group/

All sites still exist within the WP network.

Any help would be GREATLY appreciated.

Thanks,

Cam