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 are two basic ways I can think of that you could still end up using OpenDNS without setting it as your DNS server in the private DNS settings. The first is simply if it's the default DNS that your ISP (in this case the phone company, since you mention you're not on WiFi) supplies. If you don't set a DNS server, then your system will obtain one at the same time it obtains an IP address via DHCP during the initial handshake with the ISP, because it needs to use something to translate website names into IP addresses. So if the ISP is configured to suggest OpenDNS, that'll still be what you'll use. You can override this by manually setting another DNS server. Note though that many DNS services (including a Google, if I recall correctly) use OpenDNS as a fallback setting, so if the main DNS site is down for some reason, you might still get OpenDNS results.
The other possibility is if have a VPN enabled, like Adguard or DNS66. These often affect DNS resolution as part of an effort to block ads. Again, manually setting a DNS, or disabling the VPN, should override this.
One last note is that there's a setting in Chrome that lets it bypass your DNS settings and use Google's own DNS for that app, so if you're using Chrome and Google's DNS server is down or doesn't have an entry for a particular site, that could still lead to OpenDNS being used for resolution. I haven't really found turning off that setting to work in getting Chrome to use my configured DNS, which is part of why I now use Firefox on Android, but in theory it should be possible to fix with "settings->privacy and security->secure DNS->use current provider," or with a custom configuration in the same setting, in Chrome, or by turning off secure DNS in the same spot.
Note that all these settings do have privacy implications, so it might be worth reading about those before mucking with any of them!