Hello Fredik,
SAP disconnection due to WI-Fi problem clearly says the network setting issue.
I would suggest please check your network setting again.
To Avoid this type of problems we can use the below alternative option (Temporary) :-
1. Setup SAPROUTER in your landscape.
2. The Public IP of SAPROUTER should be Ping-able through your local network , WI-FI open or wired.
3. Enter the Router PUBLIC IP address details in your Router string tab in SAP GUI Logon pad.
4. Test that.
Hope this will help .
Regards
Pranay