Migrating to Omnibus Installation on Ubuntu 20 from Bitnami AWS EC2 image running on Ubuntu 14.04

Troubleshooting
1

Summary

Cannot restore Bitnami backup to new omnibus installation. When I do mmomni restore application-backup.tar.gz I get the error:
unknown file “opt/bitnami/mysql/lib/libmysqlclient_r.so.18” with type 2 found in the tarball.

Steps to reproduce

Take backup with Approach B as mentioned here: Create and restore application backups

On new mattermost Omnibus installation, restore as mentioned here: Installing Mattermost Omnibus — Mattermost 5.32 documentation

Expected behavior

I tried migrating my server to another bitnami marketplace ec2 instance but after I spawned a Debian 10 new EC2 with MM 5.32 and restoring backup the version downgrades to 5.25.0 and I cannot upgrade it again. mattermost service cannot start and I cannot get any logs from mattermost.log or journalctl

Observed behavior

What did you see happen? Please include relevant error messages and/or screenshots.
ERROR: unknown file “opt/bitnami/mysql/lib/libmysqlclient_r.so.18” with type ‘2’ found in the tarball

Please advise what would be the best method to upgrade to latest version here and move to omnibus as its easier to upgrade via omnibus and I dont want to maintain Bitnami instance anymore.

2

I have restored backup from Bitnami installation onto new instance. I have just copied /opt/bitnami/apps/mattermost/server/data/* folder to /var/opt/mattermost/data/*

And also checked the new config. As this is a new domain for new instance, I havent changed anything in new config.json.

I can see data files in /var/opt/mattermost/data now but I cannot seem to login to new domain with my old credentials. Any idea what to do here?