Synology reverse proxy internal not working

[Operations]

I am hoping someone here is also using the reverse proxy on a Synology NAS. I know about HA Proxy and i will probably end up there, but it annoys me this is not working 100% and i cannot leave it like this before i move to HA Proxy :)

Situation:
Unifi Controller on VLAN20 (subnet 172.16.20.0/24)
Synology on normal LAN (Subnet 192.168.100.0/24)
PfSense also on normal LAN
Laptop/desktop also on normal LAN

I can reach the Unifi controller on the VLAN and i can reach the Synology. The synology can also reach the Unifi Controller.

I have configured the Reverse proxy on my Synology including a Let's Encrypt SSL certificate. This seems to be working fine from the outside.
Internally i cannot open https://unifi.mydomain.com:8443, it keeps loading...

Firewalls from the LAN to VLAN20 allow all
From VLAN 20 to LAN block all to RFC1918, i have allowed all traffic to synology IP as a test. I But that doesn't change the situation.
I am not seeing anything in the FW logs.

I think this is a routing issue, but i cannot figure out how/where.

Any ideas?

[johnpoz]

@operations if your internal and hitting your pfsense wan IP, and you want to be forwarded back in to some IP (that is running a reverse proxy or anything really) you would need to setup nat reflection in pfsense.

[Operations]

@johnpoz NAT reflection is set on Pure NAT. But i am guessing i have to do more than that?