Updated my Pi-hole's from Buster to Bullseye and can't access through Nginx

Expected Behaviour:

2 Pihole's running on Raspi4B

Local dns
--> local dns set in hosts
SSL config (placed in conf-enabled) + certificates:

#Loading openssl
server.modules += ( "mod_openssl" )

setenv.add-environment = ("fqdn" => "true")
$SERVER["socket"] == ":443" {
	ssl.engine  = "enable"
	ssl.pemfile = "etc/lighttpd/ssl/combined.pem"
	ssl.openssl.ssl-conf-cmd = ("MinProtocol" => "TLSv1.3", "Options" => "-ServerPreference")

# Redirect HTTP to HTTPS
$HTTP["scheme"] == "http" {
    $HTTP["host"] =~ ".*" {
        url.redirect = (".*" => "https://%0$0")

Through Nginx proxy manager
Same config Pi-Hole
Nginx set: https://pi-hole.mydomain.be --> https://ipoffpihole:443

On Buster all working fine.

Also did clean install on a VM with same result...

Actual Behaviour:

On Bullseye:

Locals dns: working as before
Through Nginx Proxy manager: "502 Bad Gateway"

If I remove my SSL certificate from Pihole and set to proxy https://pi-hole.mydomain.be --> https://ipoffpihole:80 it's also working but then I don't have my local https anymore

What could be changed?

Debug Token:


Nginx Log:
2023/01/24 08:49:01 [error] 517#517: *1266 connect() failed (111: Connection refused) while connecting to upstream, client: "my ip adress", server: pi-hole-master.mydomain, request: "GET /admin/ HTTP/2.0", upstream: "", host: "pi-hole-master.mydomain.be"

Nginx Log (when ssl config is removed from PiHole and nginx is set to connect to http):
24/Jan/2023:08:49:01 +0100] - 502 502 - GET https pi-hole-master.mydomain.be "/admin/" [Client "my ip adress"] [Length 154] [Gzip -] [Sent-to] "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/109.0" "-"

Solved the problem.
My nginx didn't support TLS 1.3, so when setting minimum tot TLS 1.2 all was working again.