PC updates do not work with Failover.

[WhiteTiger]

I have activated the transparent Web Proxy for the HTTP protocol only.
Following the documentation I created these rules.

I also activated failover and therefore changed the gateway for "Default allow LAN to any rule".

Now, updates for Linux, Windows and some Windows applications no longer work.
Just insert an "All Opens" rule (circled in red) addressed to the default gateway and obviously everything works.

I also checked the other options for failover, but I can't find anything wrong.
I also set to Off the  option "Shared forwarding (Use shared forwarding between packet filter, traffic shaper and captive portal)".

[WhiteTiger]

I believe that the problem is limited to the use of DNS, but I'm not sure because I can't find any reports in Unbound DNS: Log File.
However, by enabling the Gateway Group in the LAN rule I then have these problems:

• Windows Update (Win 11): Cannot connect to the update service.
• Linux apt update: always reports "Failed to connect to SERVER.ubuntu.com:80".
• Portable Apps (in windows): out of 17 apps, only 14 are updated and their update address is found very, very slowly.

Instead, if in the LAN rule I enable the default gateway

• Windows Update (Win 11): Completed quickly.
• Linux apt update: Completed quickly
• Portable Apps: update up to 30 apps in just a few minutes.

I initially thought the problem was the web proxy, but I became convinced otherwise.