I have blokada on mine I had whitelisted all the amazon servers it connects with but when I read this I removed them all to stop it updating hopefully.
Will probably work until I get round to trying the xda fix.
Well mine didn't update at all until I manually added the servers from amazon it was blocking by default.
So I kind of assume taking them off again is a temporary solution. That said I can't guarantee they haven't changed anything since then and I might wake up to a worse fire cube sometime.
Blokada overrides the dns to its own and even then I don't see how dns is at all relevant because it blocks the update server from being connected with.
Firesticks use a hardcoded backup DNS which can't be changed/disabled without root access. This renders DNS level blocking useless because they'll just use their backup DNS if your DNS resolves to 127.0.0.1/0.0.0.0