Do new charms work correctly?

I'm quite confused with new charms which have been updated during the latest patch. Let's take as an example Amethyst Charm.

It says "+18% to Chaos Resistance" however then I hang it on my belt nothing changes in my character screen, it's still the same 17% of chaos resistance. However, POB says that I do get +18% if I activate this charm on Items tab.

So does it give me this increase on a constant base or I get it just then this charm does its work triggering after me being hit? It's hard to believe that it works as I hope it's too generous but in this case it means that POB works incorrectly as well?

It works the same as every other charm.

"Charms cannot be activated manually. While a charm has sufficient charges, it is used automatically when it meets the conditions specified by its implicit modifier. When used, they will grant its effect for the listed charm duration."

I don't have POB but my guess is it's showing the resist because it's toggled to active.

Theres probably a setting in the configuration tab for if charms are considered active or not for the given calculations.