Set up router as access point, get incorrect password error
I attempted to set up my old AC1750 as an access point with my Verizon FiOS Quantum Gateway modem, following the instructions here to set up WDS bridging. I thought I had done this successfully once before. But this time when I finished and rebooted the router, the ethernet connection was fine, but when I tried to connect to thw WiFi with my iPhone I got an "incorrect password" error. Of course the password that I had put in was correct. In addition, I cannot access the admin login after finishing the setup and rebooting. I had reset the IP to 220.127.116.11, and when I rebooted the router at the end, I got a page with "The connection has timed out. The server at 192.168.0.2 is taking too long to respond," and it cannot connect. The only way I can get to the admin login is to reset the router and start all over again. I've done this several times. Both problems keep happening.
One thing I did which was not strictly in the linked instructions was on the page where I put in SSID (to be bridged), with the SSID from the root modem , I also put that name at the top as the ID for the WiFi. I thought that was innocuous (and thought I had done that without a problem before), because otherwise it indicates a TP-Link network, and I thought the network name should be the same regardless of which room in the apartment I'm in. Any idea what I might have done wrong? It's driving me a bit crazy.