Windows automatically adds the virtualbox host-only network to the list of public networks. This entails that the firewall will prevent proper access.
To overcome this and not make any security breaches in your setup: go to the Windows firewall section, in Control Panel, click on advanced settings. In the page that pops up, click on inbound rules, then on new rule.
Choose custom rule, set the rule to allow all programs, and any protocol.
For the scope, add in the first box (local IP addresses) 192.168.56.1, and in the second box (remote IP) 192.168.56.0/24.
Click next, select allow the connection, next, check all profiles, next, give it a name and save.