No internet connection after school IP change

[ipadteresas]

Hi. I'm having problem to logon to Spotify app, since we change our IP range at school. We are using Spotify Premium at local primary school. I'm tech suppport here. It used to logon OK, Then after our IP changed, I get this no internet connection error massage 4 when I open spotify app. We are using proxy, but it's set up correctly in settings. Nothing change on our domain controller except IP address. I doubt it's the firewall rule need to be changed on top level domain above the school in Local education authority regarding the new IP address range. But thier IT support isn't helpful on this.  I'm completely clueless.  Is there any technical advice? Thanks. The spotify web player through webpage works though.