Hi
I found an solution
In the ladder config the httpclose (and http-server-close) did break the communication with the ADFS server.
Furthermore I tried to change the httpchk to a GET on /adfs/probe… and If I do in eg. firefox I will get an 200… but Haproxy got an 503… but When returning to /adfs/ls/IdpInitiatedSignon.aspx, and changing the following “http-check expect status 200” - all started to function as expected.
Thanks for you time
/Flemming