Invisibility effect and token visibility

Why doesn't adding the invisibility effect to an actor in the combat tracker make their token invisible? Is this is a simple fix?

You can right click on the token on the map and go to visibility and make them invisible on the map as well if you want to. The problem with doing so is that players won't be able to target the actor either on the CT or on the map. Depending on the ruleset you are using (and you should really post in the forum for the ruleset rather that the Forge), what happens when an actor goes invisible will vary. In my games (in 5e) I leave the tokens visible on the map and the CT since the invisible condition correctly gives all the necessary advantage and disadvantage to attack rolls.

Because the game/rule assumption is that an effect, like invisibility, is known to the players. It affects the mechanics of the game, but not what the players know.

Think of playing around a table top with miniatures and a map. Sure, the DM or such could remove the mini from the table, but then they would have to keep track in their head, and if one or more characters has see invisibility (truesight, etc) then they would have to put the mini back in place for those players, but not for the others...

So, it's a player vs character knowledge thing. And the assumption is that players know more than characters and need to play accordingly.

that's why I was suggesting it could be a game option. I have tested and when you turn a token invisible, it is still visible to the owner and the GM, which is exactly what you want I would assume, barring any spells.

You may find an extension that changes this behavior to what you are suggesting. And ofcourse you can always add the suggestion to the Wish List, link in Mr. Z's signature.