Hi @Anderas Rønning,
Are you using the default instance? Are the instance listening on port 1433?
If the SQL Server instance is a default instance and listen on port 1433, please ensure an exception is added to TCP port 1433 in the Windows firewall. If the default instance is listening on a non-standard port, Please refer to this article which might help.
If the SQL Server instance is a named instance and listen on dynamic port, please make sure SQL browser service is indeed started and UDP port 1434 is not blocked on the firewall between the client and the server. If you cannot do either of them, you should switch your SQL Server instance to use a static port and add static port to firewall exclusion list.
In addition, please check if there are incorrect alias on the client machine.
If the answer is helpful, please click "Accept Answer" and upvote it.