I don’t have an Ariss modem to play with so my help will be very limited, but as you already found out, it’s a PITA to bypass according to everything I read about it. I asked about the passthrough because it’s the feature used on most modems when you want to use your own router. When you said all ports are wrong after, you mean on the modem?
I understand what pcunite’s script cleverly does:
ether1 → ONT
ether2 → modem - script is used to authenticate with the ONT and port is turned off after the WAN ip is provided
ether3-ether5 → your home LAN
However, I wouldn’t even bother with the script and just remove the Ariss as soon as you get a WAN ip and power everything from a UPS to protect the network from power failure. If you remove the Ariss and connect the HAP to the ONT after you have internet, does it work with a default config?
Have you tried the supplicant method from the same thread? There’s another simple solution on Youtube which involves leasing a static ip block from your provider. The user claims that it solved all the issues he was having trying to bypass the Ariss.
If you absolutely want to use the double bridge method, I would start from scratch with a blank config and configure everything myself troubleshooting at each step. I’ve been down that path and using someone else’s config is opening a big can of worms when you have limited knowledge about ROS. The TKS videos are a good starting point with one caveat for gaming: Do not use L7 if you care about low latency gaming - the HAP is not powerful enough and it’s probably bad practice on a home network even with a 4011.