Custom types taxonomy fields looks empty

We moved a Wordpress site to a new server and now the taxonomy fields looks empty so now I can’t add new custom posts

This is how it looked before

and this is how it looks now

Any idea of what may have been causing the issue?
We are using version 4.5.4 of Wordpress and the MySQL tables seem to be OK

It’s probably something else. I could provide some paid help, if you’re interested in. Feel free to drop me an email