So the cursor in your game isn’t working, because it doesn’t bring up the interaction menu with other Zois, correct? Does it work normally with all objects and items in the world? 
Can you send a screenshot?
I’ve looked again, and my original report (I will modify it) is not quite correct. It’s not all Zois, just a few household Zois with which I usually interact. I appear to be able to click a Zoi and get an interaction menu for most Zois, in fact. Just not with several household Zois with which I commonly interact. It’s very odd.
If I change “active player” to be one of the other family Zois (from the home/family menu icons) with whom I can no longer interact with, then they also can only interact with “some” other Zois. An apparently random grouping of interactibility.
Some Zois are clickable, others not. If I change the active Zoi, different family Zois become clickable, and different family Zois not. It seems a bit like I’ve activated a “protected mode” or something, which silently changes which Zois may or may not be selected, dependent on which Zoi is active.
It’s possible I’m seeing this behaviour because the other Zoi is busy (not selectable for interaction), eg; they’re at school or doing something else entirely. But there is no indication that they are busy, just no response from the “click Zoi to select” cursor. At least this is what it looks like is happening.
There needs to be a popup/hint “this Zoi is busy (doing abc)” or something like that.
Very strange
I know that sometimes when a Zoi is busy, a very small and quick message pops up. It’s possible to miss it if you’re not looking at the upper part of the screen within a few seconds.
Could you please share the affected save file here? I’d like to check if I can reproduce your bug in my game with it. If the forum says your folder is too big, this is a short guide on how to find the correct, smaller file: How to locate which Save File to send [Guide] 