is there an option to turn off the event where sold slave return and ask to be taken back? it's starting to get annoying because it's almost 100% certainty to trigger and the devs need to understand that when player decide to sell that means they don't want it anymore, sure do 1-2 event trigger is fine for flavor, doing it all the time makes it looks broken and counterintuitive
what i find even more annoying by these events are also, when u're a paternalist kind mc and u try to sold these girls to at least a good buyer or give them prospective future, and then they'll ALWAYS return after being abused, no other variation, so like, the only WAY to ensure these girls have rather safe future outside ur penthouse is to retire them as menial, that's it
Here's a gamer metaphor to explain why these are bad UX:
You gain a new sword that has better stats than your equipped one, so you try to sell or discard the old one, but the game ALWAYS triggers an event that make the sold/discarded sword RETURNS to your inventory and waste your space/weight limit
Some of these things have already been mentioned, but:
1. Not all slaves can boomerang. Notably, they have to be devoted to you, and either completely trusting of you or completely terrified of you (plus half a dozen other conditions).
2. Slaves cannot boomerang from all buyers. Extra hint: if you're playing Paternalist, and you want a known-good outcome for a fertile slave with
zero chance of a boomerang, find either a Repopulationist or Eugenicist arcology owner to buy your slave (i.e. "a fellow arcology owner seeking a smart, pretty slave to use as a breeder to produce superior children" or "a fellow arcology owner focusing on building a future society based on his genes"). Or, as someone else noted, sell to the Peacekeepers...slaves they buy never boomerang either.
3. The world of FC is dystopian. No matter how hard you try to find good homes for your slaves, bad shit can and will happen to them when circumstances change. The safest place for your slaves is indeed in your own paternalist arcology...unless you lose the game...

4. There can only be one boomerang candidate. If you sell a bunch of slaves in a short time period, only the first one you sold has any possibility of returning.
5. It's free money. You got paid, AND you got your slave back...so you can sell her again. It's entirely a positive event, from the PC's perspective (the slave may have a different perspective, of course).
6. The boomerang event is not particularly likely. It cannot trigger before five weeks after the sale, is weighted equally to most other random nonindividual events (of which there are over 100) at five weeks after sale, and the likelihood goes
down after that. Saying it "always happens" is a bit ridiculous...it would be incredibly exploitable if it really happened with any kind of reliability. Actually it makes me wonder if maybe you're playing in a way that makes you ineligible for too many RNIE events...what FSes are you running other than paternalism, and what facilities do you operate? Do you have facility leaders in all the facilities that you operate? How many weeks into the game are you? We might need to just add a few more events to the pool that match your playstyle better. Do you find that other events in that pool also trigger very frequently (i.e. the citizen hookup event, poker night, or the old man beating his slave in public)?