[Risolto] Variations are going crazy

Background of the issue:
I am trying to fix the variations of a product on my site link nascosto. The main product is set up correctly, and I've linked all taxonomies.

Symptoms:
The variations of one product have stopped working. When I sync the taxonomies, it is creating new ones.

Questions:
Why are new taxonomies being created when I sync them?
How can I fix the variations of the product that have stopped working?