dsm6, vtiger and webserver protection

Hello,

I am a bit puzzled with this and i was wondering if you have an idea how to resolve it.

I have a local server at localhost:81 where i am running vtigercrm. I wanted to use the UTM9 to do the reverse proxy for me. However I am getting an error

The page isn’t redirecting properly

Firefox has detected that the server is redirecting the request for this address in a way that will never complete.

    This problem can sometimes be caused by disabling or refusing to accept cookies.

And when i look at the logs i don't see anything special:

2018:04:04-10:10:52 vpn-1 httpd: id="0299" srcip="source" localip="destination utm ip" size="0" user="-" host="source" method="GET" statuscode="301" reason="-" extra="-" exceptions="-" time="102534" url="/" server="dns name" port="443" query="" referer="-" cookie="PHPSESSID=112a63a65ac486f428b73" set-cookie="-" uid="WsSIjMCosgIAAEKIHjUAAAAA"
2018:04:04-10:10:52 vpn-1 httpd: id="0299" srcip="source" localip="destination utm ip" size="0" user="-" host="source" method="GET" statuscode="301" reason="-" extra="-" exceptions="-" time="98000" url="/" server="dns name" port="443" query="" referer="-" cookie="PHPSESSID=112a63a65ac486f428b73" set-cookie="-" uid="WsSIjMCosgIAAEKIHjYAAAAA"
2018:04:04-10:10:52 vpn-1 httpd: id="0299" srcip="source" localip="destination utm ip" size="0" user="-" host="source" method="GET" statuscode="301" reason="-" extra="-" exceptions="-" time="101673" url="/" server="dns name" port="443" query="" referer="-" cookie="PHPSESSID=112a63a65ac486f428b73" set-cookie="-" uid="WsSIjMCosgIAAEKIHjcAAAAA"
2018:04:04-10:10:52 vpn-1 httpd: id="0299" srcip="source" localip="destination utm ip" size="0" user="-" host="source" method="GET" statuscode="301" reason="-" extra="-" exceptions="-" time="93839" url="/" server="dns name" port="443" query="" referer="-" cookie="PHPSESSID=112a63a65ac486f428b73" set-cookie="-" uid="WsSIjMCosgIAAEKIHjgAAAAA"
2018:04:04-10:10:52 vpn-1 httpd: id="0299" srcip="source" localip="destination utm ip" size="0" user="-" host="source" method="GET" statuscode="301" reason="-" extra="-" exceptions="-" time="93117" url="/" server="dns name" port="443" query="" referer="-" cookie="PHPSESSID=112a63a65ac486f428b73" set-cookie="-" uid="WsSIjMCosgIAAEKIHjkAAAAA"
2018:04:04-10:10:52 vpn-1 httpd: id="0299" srcip="source" localip="destination utm ip" size="0" user="-" host="source" method="GET" statuscode="301" reason="-" extra="-" exceptions="-" time="100417" url="/" server="dns name" port="443" query="" referer="-" cookie="PHPSESSID=112a63a65ac486f428b73" set-cookie="-" uid="WsSIjMCosgIAAEKIHjoAAAAA"
2018:04:04-10:10:53 vpn-1 httpd: id="0299" srcip="source" localip="destination utm ip" size="0" user="-" host="source" method="GET" statuscode="301" reason="-" extra="-" exceptions="-" time="99460" url="/" server="dns name" port="443" query="" referer="-" cookie="PHPSESSID=112a63a65ac486f428b73" set-cookie="-" uid="WsSIjMCosgIAAEKIHjsAAAAA"
2018:04:04-10:12:54 vpn-1 httpd: id="0299" srcip="destination webserver ip" localip="destination utm ip" size="277" user="-" host="destination webserver ip" method="GET" statuscode="200" reason="-" extra="-" exceptions="-" time="4760" url="/rest/capabilities/navigation" server="issues.savagi.net" port="443" query="?lang=en-GB" referer="-" cookie="-" set-cookie="atlassian.xsrf.token=BBIH-2B6M-X92B-L2R1|78b2263ce25052ade10411d992436f8724dca63d|lout;path=/" uid="WsSJBsCosgIAAEKIHj4AAAAB"
2018:04:04-10:16:48 vpn-1 httpd: id="0299" srcip="destination webserver ip" localip="destination utm ip" size="308" user="-" host="destination webserver ip" method="GET" statuscode="200" reason="-" extra="-" exceptions="-" time="6505" url="/rest/capabilities/navigation" server="kb.savagi.net" port="443" query="?lang=en-US" referer="-" cookie="-" set-cookie="-" uid="WsSJ8MCosgIAAEKIHkAAAAAE"

I also tried combinations of Disable compression support, Rewrite HTML, Rewrite cookies, Pass host header but it didn't work out.

Do you guys have an idea what am i doing wrong?

Same problem with DSM 6.

Thanks!