Cant reach NAS2 from WAN, can reach NAS1 from WAN

[Modesty]

Hi

I have 2 NAS's

The one NAS that i struggel with is Synology DS920+, the one that work is a Netgear

I have 1 rule for NAS 1, that works!

NAS1

WAN xxx.dyndns.org:8888

NAT rule1 port 8888->80

NAS2
For NAS 2 I made a copy of NAT rule1 ->Rule2

WAN xxx.dyndns.org:7890

NAT rule2 port 7890->7890

"This site can't be reached"

The difference as I see it:
NAS1 has http port 80 - Netgear
NAS2 has http port 7890 - Synology

Thanks up front

[viragomann]

@modesty
It's basically not a good idea to expose a NAS to the internet at all. However, that's your decision.

I suspect the issue won't rather be the NAS itself than the firewall rule or the port. I guess, the Synology might block access from IPs outside of its own subnet.
You will have to allow that on the NAS itself.