Site Migration - Custom field connections are gone

Migrating from shared hosting to vps (lightsail) that is managed via ServerAvatar and noticed the custom fields are not connected to the posts.

First I tried backing up / restoring with wpvivid: They are messed up

Then manual migration (copy wp-content folder, export/import database and connecting it via wp-config.php): They are messed up

Now clean install again and using wordpress native export/import tool: They are messed up

In any of these cases if I try to edit any of the field groups on the new site, they just keep loading. "Loading fields, please wait..."

I've lost like 12 working hours so far trying to solve this. At some point I was thinking that maybe it has something to do with the db charsets as they differ between the WordPress intallations. https://stackoverflow.com/questions/71540009/mysqldump-import-into-db-with-different-charset-from-unicode-520-ci-to-utf8mb4 (Not sure if this is related at all. It's just one of the few google results regarding migration between exactly same database charsets that I am working with)

But then again after doing the native WordPress export/import and failing on that as well made me think that the charsets probably have nothing to with the issue.

Could you please provide some assistance? I am seriously losing my mind here.