Thanks for doing that search, I'll address each site:
https://tenzer.dk/nginx-with-dynamic-upstreams/
This seems to be relevant to DNS names changing:
"Closing words
Just to make it clear, this doesn't only affect setups using an ELB as an upstream server, but applies to any configuration where you use a changing DNS record as your upstream server in Nginx."
Mine aren't, so I'm not sure that's the isuse.
http://stackoverflow.com/questions/24350124/port-number-getting-stripped-out-of-url
I can't really sort out what the fix was. It sounds like it was addressed within the application and not Nginx.
https://forum.nginx.org/read.php?2,239790,239794#msg-239794
I'm using 1.9.15 so I'm not sure if this is relevant.
https://tenzer.dk/nginx-with-dynamic-upstreams/
This seems to be relevant to DNS names changing:
"Closing words
Just to make it clear, this doesn't only affect setups using an ELB as an upstream server, but applies to any configuration where you use a changing DNS record as your upstream server in Nginx."
Mine aren't, so I'm not sure that's the isuse.
http://stackoverflow.com/questions/24350124/port-number-getting-stripped-out-of-url
I can't really sort out what the fix was. It sounds like it was addressed within the application and not Nginx.
https://forum.nginx.org/read.php?2,239790,239794#msg-239794
I'm using 1.9.15 so I'm not sure if this is relevant.