Thinkpads and USB-C charging firmware issues

I would like to learn more about the issue with Thinkpads and USB-C charging. I first thought that it was the solder going bad, but I read somewhere that this is actually a firmware issue where the port gets progressively worse and then stops working.

What is it exactly? I bought an old T14 G1 and I want to make sure that this doesn't happen to it.

Thank you!