Indirect Connection within local network

I feel like I am a pretty strong Plex user, and I have changed nothing in chrome from last week to last night/today. As of right now, Chrome still fails to connect directly to my server.
I had attempted to log out then back in, and even tried it in incognito mode. In the latter settings, I got an interesting error when I logged in, it stated “Your credentials have expired, please log in again.”, but upon hitting OK on the prompt it did nothing more than present my normal server homepage. A page refresh did not yield a prompt to login, nor did it warn me of my credentials. This is the same error you get when a client has been deleted from the “Authorized Devices” panel of account settings.

As for DNS rebind protection, I have not had an issue in the past, and have not logged into any of my routers to enable the feature recently. I will check for the existence of the setting, and whether it is set, but as this issue does not happen on a different browser on the exact same computer, it seems unlikely to be a router-based setting.

DHCP on the router is currently set to use the ISP’s default, and I am not using an alternate DNS in my own network settings. I may fiddle with that in the future, but again seems like a bad direction to go if this exact same computer can connect directly using Firefox, but not Chrome.

My network is fairly simple. While I have a wi-fi router in the home, my computer and my server have no wireless card, so use the home modem/router’s DHCP setting in the 192.168.0.x network. Wireless devices are on the 192.168.5.x network, but are routed properly and do not currently have this issue, only Chrome on my Wired desktop computer.

Edit: I’m going to check out the rather large forum post I’ve seen here lately about people being unable to log in, getting an Internal Server Error upon login. I am not getting this issue myself, but I wonder if my inability to connect directly might be related somehow…