I've been looking this up for days, and at a complete dead end now. Everything I find basically comes down to remove the dns address, turn it off, or change the address to 1.1.1.1. None of this works.
You can see in the picture that it's turned off, and there are no saved addresses to remove. It won't even save an address if I enter one. I can't find anything else on my phone that references dns or network settings. I'm only using cell data, not connected to any wifi. Changing the setting to automatic doesn't do allow me to visit sites either. Changing a setting and power cycling the phone doesn't change anything.
I've spoken with my carrier, there are no parental blocks on my account. I'm the only person on the account. No one else has access.
When I go to a site my browser tells me the site is not secure, mentions opendns, and gives me the option to continue anyways. Doing so only routes back to the same not secure message. I can't go any further.
I have no idea how this got on my phone, but it's been on it for a couple months now. I'm sure I'm forgetting some info, but I've listed the main things. Any help would be appreciated, this is just stupid at this point.
If there's a better /c/ to ask about this in let me know. Thanks everyone!
EDIT: Lem453 got me back online with thier suggestion. Select the bottom option “private DNS hostname” and enter either one.one.one.one or DNS.google.com.
Lots of good info provided by people too in the comments. As much as this has been frustrating for me on a daily basis it's also given me new knowledge on how my phone works, so that's pretty cool.
There's always a router, and there's always a DNS server. Normally, your device is asking to join a network, and something on that network assigns it an IP address, a DNS server, and a gateway router to use. That's true whether you're connecting to WiFi or a cellular network. The difference is just which device is assigning you those things. You can also override that on your side by specifying a static configuration that can break things, but I don't think that's your problem.
"Private DNS Mode" here is only referring to whether or not you want to encrypt the DNS lookup traffic. That's certainly not a bad idea, but it's a separate issue from whether or not you have a working DNS setup at all. From the screenshot below, it looks like you do have a working DNS configuration. To connect to a server, you type the server's name (e.g., mobile.pornhub.com), your browser sends a DNS request to your DNS server asking it to return the IP address of that server, and then it uses that IP address to ask the server to send it a web page. You're getting to the part where you've asked the server to send you a web page, but the server is refusing because your browser didn't make the request over HTTPS (i.e., using encryption).
I don't know why that is, but I'd try the steps outlined here.