Unable to load backend servers URL via haproxy - load-balancing

Question

when we hit https://abc.domain.com/global its able to reach the backend server but the page keeps on loading. direct links to backend servers work and able to telnet to the servers as well. for ex https://srv1:8180/D2 and https://srv2:8180/D2 works
Could anyone please suggest what is missing? this is my first handson on haproxy. Selinux is disabled. haproxy server on redhat 7.9 and haproxy version 1.7.1
Below is the configuration file
defaults
mode http
log global
option httplog
#option dontlognull
option http-server-close
option forwardfor except 127.0.0.0/8
option redispatch
retries 3
timeout http-request 10s
timeout queue 1m
timeout connect 10s
timeout client 1m
timeout server 10m
timeout http-keep-alive 10s
timeout check 10s
maxconn 3000
stats enable
stats uri /stats
stats realm Haproxy\ Statistics
stats auth *:*
frontend https-in
mode http
bind *:443 ssl crt /etc/pki/tls/private/haproxy.pem
# redirect scheme https if !{ ssl_fc }
acl test_host hdr(host) -i abc.domain.com
acl d2nsh path_beg -i /global
use_backend testd2nsh if test_host d2nsh
frontend http-in
bind *:80
mode http
option httplog
##
acl test_host hdr(host) -i abc.domain.com
##
acl d2nsh path_beg -i /global
##
##
backend testd2nsh
mode http
balance roundrobin
option httpclose
option forwardfor
cookie JSESSIONID prefix nocache
reqrep ^([^\ :]*)\ /global/(.*) \1\ /D2/\2
server srv1_8180 srv1:8180 ssl verify none check cookie s1
server srv1_8190 srv1:8190 ssl verify none check cookie s2
server srv2_8180 srv2:8180 ssl verify none check cookie s3
server srv2_8190 srv2:8190 ssl verify none check cookie s4
##

Answer 1

Which version of HAProxy do your use?
haproxy -vv
Just a wild guess but on the srv*:8180 does not exist the /global URL and your get a redirect to https://srv*:8180/D2
If this is the case then try to set the path in the backend.
http-request set-path
backend testd2nsh
# other configs
http-request set-path /D2
# rest of the config
Some of servers and applications can be configured to know that they run behind a reverse Proxy and adopt the redirects like the tomcat