I have the exact same problem as Muzlap. I tried everything, but I can't get the proxies to work - been doing this for a whole day now. There are no errors, it just looks like it works perfectly but I can't seem to connect to them and proxychecker tells me they are still dead.
Does it have something to do with the fact that we have to change something in the Network interface since we use a later version of Ubuntu (16 or 18) instead of the author of this article (which was using 14)?
The IP adresses we are using are IPv4 Public IP's of the AWS or additional IPs, right? Even when just trying to use the AWS as a proxy, it still doesn't work for me..