trying to turn this router into wifi → wifi + ethernet thing, it kinda works but mostly doesn’t

got a TL-WA901ND v4 with some custom firmware on it (openwrt 18.06.9 or whatever) basically what I’m trying to do: connect the router to another wifi network then have it give me internet through BOTH its own wifi and the ethernet port important part: I don’t want it to just “extend” the network, I want it to make its own separate network (different IP range) so like: main router → (wifi) → my box → (new wifi + ethernet) I managed to get it to connect to the main wifi somehow and also made it broadcast its own wifi devices connect to it fine, they get IPs and everything BUT internet is super inconsistent sometimes it works, sometimes no internet, sometimes stuff loads but DNS seems broken ethernet to my PS4 works better but still randomly acts up I have no clue what I’m doing wrong I clicked around a bunch in the web UI and set things that sounded right (DHCP, WAN, LAN, firewall?? idk) now it’s just cursed do I need some extra package or something for this setup? or is this router just too old / weak to do wifi in + wifi out at the same time? not trying to do anything crazy, just want it to take wifi and spit it back out as its own network + ethernet someone explain this like I’m stupid because at this point I clearly am

i've reset the route, don't ask about any changes made as there are none. treat this as a fresh install.

I don't think it would be possible to have wifi in+out unless you had seperate wifi radios on the motherboard. Usually that's the case. The most you could do is set the wireless interface as the connection to your main router, and then use one of the ethernet interfaces to connect another access point only operating as a layer 2 device, so that you can wirelessly connect your devices, but the new router can still assign IPs and create routes. Out of curiosity, why don't you want it to act as an extender? Are you trying to hide your devices from the main router or something?