What is keeping "Flow Cache" in "Disabled" state on my RT-AX86U?

[rkk2025]

Hi, I'm trying to get "Flow Cache" to be "Enabled" in my RT-AX86U. I had previously AiProtection enabled and had briefly "Adaptive QoS" enabled too to experiment with it. As far as I'm aware these are the most common options that are mentioned that could Disable "Flow Cache". So now I have "AiProtection", "QoS", "App Analysis", "Web History", "Statistics" and "Game Boost" all off/disabled. And after rebooting the router I get "Flow Cache" in "Disabled" state. What else could be disabling it?

I seem to be able to Enable "Flow Cache" temporarily by running "fc enable". But after rebooting the router, it's in "Disabled" state again.

Is there any way to find out what exactly keeps disabling "Flow Cache" on my router? Am I missing out something?

 

[ColinTaylor]

Have you ever installed the Wireguard addon script?

Check that these variables are =0

# nvram show | grep ^fc
fc_disable=0
fc_pt_udp_war=0
fc_pt_war=0

 

[rkk2025]

Have you ever installed the Wireguard addon script?

Check that these variables are =0

# nvram show | grep ^fc
fc_disable=0
fc_pt_udp_war=0
fc_pt_war=0

Yes, I'm indeed actively using Wireguard for a permanent Site-to-site connection (With the Wireguard addon script enabled).

I have "fc_disable=1". I change it to =0 and will see how that affects Wireguard. I also had to change wg_manager.sh to avoid having it disable Flow Control on every boot. (Because for some reason that has been hardcoded in the script for this particular router model)

Flow Cache seems to be enabled and working now (Even after reboot). Thank you @ColinTaylor for pointing me to the right direction.

PD: I was not able to repro the performance issue with Wireguard with Flow Control enabled on my RT-AX86U with AsusWRT-Merlin 386.7. I'll keep an eye on it, but so far VPN performance and CPU usage seems to be working pretty fine.