In your first post (and your picture) is a path:
Maybe you could check there. And yes, your LaTeX syntax on your card is correct, so this isn't part of the problem.
Anki loads a lof of packages, so maybe some packages are updated and have commands with the same name, what could cause these
command \(n)CI already defined errors. I would try to find this generated tmp.tex and make a testing copy. In this copy, I would remove all packages (or comment them out) and enable them step by step to the point/package where this problem appears for the first time. I would try to disable the package in Anki, if that was possible.
Personally, my experience with Anki is very limited, I'm just familiar with LaTeX and confusing LaTeX debugging. If I checked the Anki website correctly, the current version was published in 2016? Please correct me, if I'm wrong. So it's based on the versions of packages from 2016. A few years later, today, packages could act a little bit... weird, causing such errors.