$ua->proxy(['http'], $cur_proxy);

It's here, $cur_proxy should be a string looking like this: http://111.111.111.111:12345/, randomly chosen from array . If I use $cur_proxy, this string is ignored, and traffic goes directly without any proxification. But if I comment out:

 my $cur_proxy = $valid_routes[$j];
 $ua->proxy(['http'], $cur_proxy);
[download]

and rewrite it like this:

 $ua->proxy(['http'], 'http://111.111.111.111:12345/')

traffic goes through a proxy, as it should. So I need to make rotation work, somehow.