@Hotblack How to turn off your ISP router wireless radio - details for a TP-Link device - it should be similar for your ISP router. If you configure AX23 in AP mode you should not turn off the DHCP...

@svenWA Having said that you're using FTTP service from Optus, it seems that the network protocol encapsulation should be IPoE, which in terms of TP-Link should correspond to Dynamic IP. That is...

@Hotblack "...is there a way for the sockets on the modem to work? " - This question can be answered by your ISP. " Maybe I keep the ISP router and just use it to connect the phones? " - You could do...

@Areks It's easy actually - just use different SSIDs for different wireless bands. Thus you'll know to which wireless band of your AX90 you're connected at any time. When you need a wireless client...

@rossack Yes, you have that option. Actually load-balancing feature has nothing to do with having your public IP address on the TL-R470T WAN interface. The double NAT matters only if you have any...

@rossack I just noticed that you mentioned your ISP is using PPPoA connection type. The story I pointed you, gives an example with PPPoE encapsulation. It would be best to contact your ISP and ask...