@Arsie
Well if the port is showing open, then it can`t be a firewall issue, it has to be the way you are accessing it.
I assume that when you turn Wi-Fi off, you are using mobile data?
I am not sure what version of the app you are using, but on my version there is a "GET IPS" function which uses the first and last five values from your licence code. That updates the details on the Server Login screen so it shows both the LAN and WAN settings. You then have to save those settings.
I use a third party DDNS service which maps to a web address, instead of Blue Iris free one, as it saves updating the server settings manually.
Have you tried a direct access not using the app? The Chrome browser works very well for this, but you would need to use a laptop connected to your phones hotspot, to ensure a remote connection.
I cannot really offer any more advice, but you could always ask on one of the forums https://ipcamtalk.com/forums/blue-iris.30/
I can do a check from here, to see if I can see your server page?
If you want me to try, then if you send me a private message with your current public IP address, and which port your BI server is operating on, I can confirm whether I can see the login screen.
