Too many redirection with https board URL

[citrixws]

We are running on IPB 3.x and planning to migrate to 4.x . In our current  setup (IPB 3.x)  , we have a load balancer ( https ) which forwards the request to  App server on port 80 ( running apache) and we don' t get any warning in browser console for insecure content . 

Wherein the same setup does not work with 4.x , we see below error in the browser console and the login also does not work without sso. "Mixed Content: The page at 'https://<<URL>>/' was loaded over a secure connection, but contains a form which targets an insecure endpoint 'http://<<URL>>/search/'. This endpoint should be made available over a secure connection" 

As a fix , we tried to update the INFO [board_url] to https , while we do that it creates an indefinite redirection loop , which understandable as https gets you to the load balancer whenever you hit  https://<<URL>>  

Can someone help on this ?  

[Numbered]

Simple question for that setup with load balancer. Best way for you - see access and error logs from you web server. You can enable detail verbosity to see redirects for example. And be better, if you show your web-server configs. It's no IPB problem - it's incorrect web-server or balancer working. And why you have it directly? Your balancer can check load of any backend nodes? In your situation I think your load balancer try to himself. Or you backend web-server try to redirect you on right uri.

In our cluster configuration we have 1 master server and 5 slaves. Nginx working on master and forward request to random PHP backend. So it's very simple and reliably. Db is on db-host, of course.