Ha proxy and home assistant

[t.moro]

I've a problem conntecting from outside to home assistant behind ha proxy.
If I set a direct nat roule to port 8123 all works good, but if I try to use the haproxy link to the backend I receive a 503 error page.
This is my ha config, any idea?
p.s. all other backends are working correctly

# Automaticaly generated, dont edit manually.
# Generated on: 2023-07-31 19:46
global
	maxconn			1000
	stats socket /tmp/haproxy.socket level admin  expose-fd listeners
	uid			80
	gid			80
	nbproc			1
	nbthread			1
	hard-stop-after		15m
	chroot				/tmp/haproxy_chroot
	daemon
	tune.ssl.default-dh-param	2048
	server-state-file /tmp/haproxy_server_state

frontend http
	bind			192.168.1.220:80 name 192.168.1.220:80   
	mode			http
	log			global
	option			http-keep-alive
	option			forwardfor
	acl https ssl_fc
	http-request set-header		X-Forwarded-Proto http if !https
	http-request set-header		X-Forwarded-Proto https if https
	timeout client		30000
	http-request redirect scheme https 

frontend https_443
	bind			192.168.1.220:443 name 192.168.1.220:443   ssl crt-list /var/etc/haproxy/https_443.crt_list  
	mode			http
	log			global
	option			http-keep-alive
	option			forwardfor
	acl https ssl_fc
	http-request set-header		X-Forwarded-Proto http if !https
	http-request set-header		X-Forwarded-Proto https if https
	timeout client		30000
	acl			ha	var(txn.txnhost) -m beg -i ha.mysite.org
	acl			NAS	var(txn.txnhost) -m beg -I nas.mysite.org
	acl			www	var(txn.txnhost) -m beg -I www.mysite.org
	acl			proxmox	var(txn.txnhost) -m beg -I proxmox.mysite.org
	acl			firewall	var(txn.txnhost) -m beg -I firewall.mysite.org
	http-request set-var(txn.txnhost) hdr(host)
	use_backend ha_ipvANY  if  ha 
	use_backend NAS_ipvANY  if  NAS 
	use_backend serverweb_ipvANY  if  www 
	use_backend proxmox_ipvANY  if  proxmox 
	use_backend firewall_ipvANY  if  firewall 

backend ha_ipvANY
	mode			http
	id			102
	log			global
	timeout connect		30000
	timeout server		30000
	retries			3
	timeout tunnel 60000s
	server			ha 192.168.1.138:8123 id 103 ssl  verify none 

backend NAS_ipvANY
	mode			http
	id			100
	log			global
	timeout connect		30000
	timeout server		30000
	retries			3
	server			nas8 192.168.1.112:8080 id 101  

backend serverweb_ipvANY
	mode			http
	id			104
	log			global
	timeout connect		30000
	timeout server		30000
	retries			3
	server			www 192.168.1.239:80 id 105  

backend proxmox_ipvANY
	mode			http
	id			106
	log			global
	timeout connect		30000
	timeout server		30000
	retries			3
	server			proxmox 192.168.1.236:8006 id 107 ssl  verify none 

backend firewall_ipvANY
	mode			http
	id			108
	log			global
	timeout connect		30000
	timeout server		30000
	retries			3
	server			firewall 192.168.1.1:80 id 105

Thanks