SQL connection only possible from local network?

I'm very young (14) and am currently working on VisualBasic and SQL Server. An SQL server is set up and running on my desktop PC. In the FritzBox I released the port TCP / 1433 (also in the Windows firewall). Checkmark for "Allow remote access" is inside and the IP settings in the configuration manager are also correct. My only problem is that I can easily log into the server via the IP address of my PC (from wieistmeineip) from my laptop (or via the PC name). However, if I log in to my neighbors' guest Wi-Fi (with a laptop), I can't access the SQL server via the IP address. The whole thing actually only started when I wanted to do a login form in VB, but I can't access the IP from a foreign network. In short: I can access the server from my own network both in the application and from the Management Studio, as soon as you try it from another, it no longer works.

Thanks for answers or suggested solutions. And try you guys. To be understood in an understandable way, because as I have already written, I'm new to the topic

Which internet provider do you have?

I unfortunately can't help you but maybe I have an internet block fie starts at 22:00 o'clock and I can't do anything because of the whitelist or blacklist and I do not want to do anything like router reset etc everything is noticeable

This is a security feature that you shouldn't disable. Almost all sql servers are configured this way.

Have you tried another network? For the guest network you can set "only web and mail allowed" in the Fritzbox, if that is with your neighbor, you will not be able to get out of his network.

Everything should be set correctly on the desktop PC and laptop, otherwise it would not work in the LAN. Either in the guest network, the port is closed, or your release configuration in the Fritzbox is wrong.

Internet provider from a town nearby. Why?

Thank you for the reply. I try it now via a cell phone hotspot, i.e. My cell phone via W-Lan with the laptop and then I try to connect. Hope it works.

You already know that the girlfriend web server is also a database server? You can then easily do this with PHP, for example. It would also be dangerous if you had access to the Girlfriend database.

Some Internet providers use techniques such as DS-Lite where you do not have a correct IPv4 address or share it with others. Port releases are not possible, this could possibly be due to this.

OK thanks

Port releases are possible with me a Minecraft server also works.

How do I deactivate this safety function? (Only out of interest I now know that it is dangerous)

I would like to put it nicely: If a lock is installed, then there will probably be a reason.