@Kevin_Z Thanks for your comments. Since you responded, some more details may be useful. As you can tell, I'm just using the router for Internet only. When I called tp-link tech support, they said to...

Hi to all Here's my experience trying to connect the Archer C64 (replacement router) to a much older ZXA10 Optical Network Terminal (ONT). This connects to a fiber line provided by Singtel in...