As you are not able to contact the root servers - or, in fact, any DNS server on the Internet, you cannot use unbound as your own resolver as it won't be able to do the recursion for you.
I'd suggest contacting your ISP and asking them if/why they are doing this. Typically, they are helpful (after all you pay them). In my case, for instance, my ISP blocked all inward traffic and I could only use Wireguard once I contacted them and they removed this "extra protection" for me.
In some sense, the DNS rerouting can be understood as a similar mean of "extra security" as it will enforce devices with hard-coded DNS server addresses to go through their servers so they can apply by-law DNS filtering (depending on the country you live in this may or not be a thing).
I wish you all the best with you endeavor of getting the full-featured version of the Internet Sun is just getting up in Germany right now (8:30 AM). Take care!
You can use the commands above
to check if it worked. And in case you need further assistance, we are here!
Heh, you are the native speaker here I'd imagine something along the lines of
Hey, I want to set up my own recursive DNS resolver for private use. However, I realized that all my requests on port 53 get rerouted to one and the same server identifying itself as "dnsmasq-2.57-OpenDNS-1". Please disable this rule for me so I can contact DNS servers in the Internet directly.
Just FYI: dnsmasq-2.57 has been released back in 2011 ...
Sun is just getting up in Germany right now (8:30 AM). Take care!
I'd imagine something along the lines of