[BUG] Initial commit hash diverged?

[ulvida]

To propose PRs to the upstream I maintain a branch upstream-main, with identical history of main branch o the upstream.

I just tried to update this branch and it said:

ulvida@paname:~/tech/interior/UdelaRInterior/udelarinterior.bind9$ git status
On branch upstream-main
Your branch is up to date with 'origin/upstream-main'.

nothing to commit, working tree clean
ulvida@paname:~/tech/interior/UdelaRInterior/udelarinterior.bind9$ git remote -v
origin	[email protected]:UdelaRInterior/ansible-role-bind9.git (fetch)
origin	[email protected]:UdelaRInterior/ansible-role-bind9.git (push)
upstream	https://github.com/systemli/ansible-role-bind9.git (fetch)
upstream	https://github.com/systemli/ansible-role-bind9.git (push)
ulvida@paname:~/tech/interior/UdelaRInterior/udelarinterior.bind9$ git pull upstream main
From https://github.com/systemli/ansible-role-bind9
 * branch            main       -> FETCH_HEAD
fatal: refusing to merge unrelated histories

I tried even to create a new branch at the initial commit to recreate upstream main, but there I realize we have a different hash of the initial commit in our repo:

ulvida@paname:~/tech/interior/UdelaRInterior/udelarinterior.bind9$ git log
commit 101b5bdb3028abdc61336d04acf0533ece1f567a (HEAD -> upstream-main2)
Author: doobry <[email protected]>
Date:   Wed Apr 18 21:28:54 2018 +0200

    Initial commit

and the upstream repo :

Initial commit

@[doobry-systemli](https://github.com/systemli/ansible-role-bind9/commits?author=doobry-systemli)
doobry-systemli committed on 18 Apr 2018
0 parents commit cd46735c995ee4a52c6f5672be5a0167e62fd4f

How could this happen? One of us did very dirty epo management?