You sure that wasn’t an alcohol free beer? Unless it’s de-alcholized beer, a non-alcoholic beer is stopped being brewed before a lot of the sugar from the yeast is turned into alchohol.

So they tend to be sweeter unless they add some additives, and they taste like stale alcohol as well, that could have been the disinfectant tinge. As they are still 0.5% alcohol typically.

Sweet beer?

What brand was it. Beer is bitter, not sweet unless you add some fruit or it’s mixed beer with juice something else.

Beer should be barley (wheat/rice/etc), hops, water, and yeast. That’s it.