Hello @Qoom and welcome to the TeamSpeak Forum.
The following Servers are working / dont work for me:
de-5.tsproxy.lol:35583 
The Server at this address is not working, so no one can connect to it
Please check that the address you entered is correct; there may be a typo. Please contact the Server Owner or the Host for more information.
celestialbeing.ts3.se Failed to resolve hostname celestialbeing.ts3.se
[Temporary Solution] You should be able to connect to the direct TS3 server address: 51.38.159.183:9717 but you still need a Password to connect at all. The same Server IP address that you have already mentioned. If you can’t connect at all, then please try the following Solution:
a) VPN connection. With connected VPN all your traffic transferring through a tunnel, so you will bypass any restrictions caused by your ISP or a home router.
You can search more about VPN in Internet and rent a proper variant of VPN. There are both free and paid VPN services. Pay attention on whether UDP traffic is allowed, because it used by Teamspeak 3 client.
b) Connect other ISP. You will have another IP address, so a route should be changed.
Or take have a look into this Thread:
