Hi @dani69654,
If you want to deploy upgradeable contracts with Truffle then I recommend using OpenZeppelin Upgrades Plugins: https://docs.openzeppelin.com/upgrades-plugins/1.x/truffle-upgrades
I created a guide walking through the process of testing, deploying, transferring control of upgrades, testing upgrades and upgrading: OpenZeppelin Truffle Upgrades
The plugins use a Proxy Admin, as well as providing an easy to use API. I would recommend trying it out.
The proxy contracts have been moved to OpenZeppelin Contracts (OpenZeppelin Contracts 3.2 - Release Candidate) if you really wanted to deploy directly.
As for your tests, can you check that your go function is actually being called.
Can you add a check for checking the variable?