Sync 2 remote repositories script - Just define the 3 variables (use export command for that!)

2repos-sync.sh

#!/bin/bash

# REPO_NAME=<repo>.git
# ORIGIN_URL=git@<host>:<project>/$REPO_NAME
# REPO1_URL=git@<host>:<project>/$REPO_NAME

rm -rf $REPO_NAME
git clone --bare $ORIGIN_URL
if [ "$?" != "0" ]; then
  echo "ERROR: failed clone of $ORIGIN_URL"
  exit 1
fi
cd $REPO_NAME
git remote add --mirror=fetch repo1 $REPO1_URL
if [ "$?" != "0" ]; then
  echo "ERROR: failed add remote of $REPO1_URL"
  exit 1
fi
git fetch origin --tags
if [ "$?" != "0" ]; then
  echo "ERROR: failed fetch from $ORIGIN_URL"
  exit 1
fi
git fetch repo1 --tags
if [ "$?" != "0" ]; then
  echo "ERROR: failed fetch from $REPO1_URL"
  exit 1
fi
git push origin --all
if [ "$?" != "0" ]; then
  echo "ERROR: failed push to $ORIGIN_URL"
  exit 1
fi
git push origin --tags
if [ "$?" != "0" ]; then
  echo "ERROR: failed push tags to $ORIGIN_URL"
  exit 1
fi
git push repo1 --all
if [ "$?" != "0" ]; then
  echo "ERROR: failed push to $REPO1_URL"
  exit 1
fi
git push repo1 --tags
if [ "$?" != "0" ]; then
  echo "ERROR: failed push tags to $REPO1_URL"
  exit 1
fi

same issue

The starting point of this script is that the sync is one-directional. If it is not from the start, it won't work.
Seems to me you have changes on the cloned repository that are not in the source repository. This won't work.
I've written this script 5 years ago where forks were not that good in all the Git-hosting services such as GitHub, BitBucket, GitHub and the rest. I suggest that you'll use forking or other more modern sync tools instead of this script which is limited.