In order for us to provide better support, we need to see the log generated by citra. This guide will walk you through how you can obtain the log file: How to Upload the Log File
When you host using Hamachi, ignore the whole Web Service function in Citra and instead focus on hosting the room as unlisted then the others in your Hamachi network can join with your virtual IP using the Direct Connect to Room option under Multiplayer.
Is there any way for the person Hosting the room as Unlisted to choose which IP gets used? I have seen the option for Citra Android users, but I do not have the option on PC it seems. I want to use my Virtual IP (as seen in the Hamachi application) as the host so I don’t have to worry about enabling port forwarding.