Hi guys,
I've been away for work as i said before and now in italy there is what it seems to be like the usual pre-covid flu epidemic where there is like 2/3 of the staff ill and the rest of us has triple work to do. Still i didn't forgot about this problem and your kind help but i must say that after setting unbound up with DoT + pi-hole + VPN i had 0 problem at all and remembering the stubborness and downthehole-ness type of reaction that this problem caused me makes me wonder if i really should open this chapter again.
Before going away last time i decided that as i was still fresh in linux terminal it would have been a good idea to have a total different image completely clean in another sdcard i had around so i did just that and it took me less than a day to setup.
This means that i still have the original sd card that we debugged together here, but after what i tried even in the new sdcard (below) i believe it could be best to just start fresh in the future 'cause maybe the problem it's not in there. Now, to explain:
Even if i did not answer i tried
with no resolution of the problem.
I tried the post before too with the same result.
After that I was exhausted and i decided to give it just one last, desperate, shot.
I went to the official unbound site and i saw the repository was behind lots of versions. So i deleted all the folders that i had messed up with and compiled the last version of unbound ( .19 i believe ) hoping that it would solve the problem. It didn't. Well, it was a mess, with different configuration folders and files in places i've never seen before. Still i downloaded the official manual and tried to make it work but after another night wasted i quit.
When i set up the new sd, unbound DoT was the target. Still, as it was an empty image i had to try to follow the official guide again and see if, with nothing messed up it would work.
And.... It didn't. I assured the time was right ( forgot to run timedatectl, just checked in raspi-config and watched my Apple watch just in case ) and all the configuration was default.
After that i decided to give up and configure DoT leaving the problem to a future me.
I'm gonna have the recursive DNS one day but i guess that day it's not today.
I will look at this post from time to time just out of curiosity and maybe some day and when the unbound package will get an update through repository i will come bite you in the arse again with a new post... but i hope not!! 
I thank you all again for your time and patience, @Bucking_Horn you most of all, i didn't think there was someone so patient and caring, i hope to find you here if i'd need help again.
Much love and respect,
Lory