Static IP WAN.

I create two different UDP port forwarding rules in the Transmission->NAT->Virtual Server tab.

I reboot the router.

The first rule doesn't work. The second works.

I reboot the router again.

The first rule works. The second one doesn't work.

Forwarding works randomly.

Sometimes forwarding does not work at all.

It does not depend on the number of rules.

It does not depend on the number of WAN interfaces.

The rules start working if you go to the Transmission->NAT->Virtual Server tab and for each rule click Disabled and then Enabled.

I checked on different firmware, it does not work everywhere.

ER605(UN)_V2_2.0.0 Build 20220106

ER605(UN)_V2_2.0.1 Build 20220223

ER605(UN)_v2_2.0.2_20220727 - beta

I assembled a stand from two laptops and watched Wireshark. From the WAN side, when accessing the forwarded UDP, it issues an ICMP port unreachable.