is there anyway to save them? or to stop them triggering?

if i send all the synth to their own settlement so theres only synths will they never trigger?

kind of attached to my settlers dont want lose any and just had couple trigger in sanctuary including one of my favourites

do settlers randomly get replaced or whatever or are they synths when they are first rolled/spawned?

Minigun coverage of Fast Travel arrival Mats. This may cause the Misc Quest to stop attack at Settlement X to fail, but the Synth Infiltrator will not survive.

What?

OP how do you know if one is a Synth so that you can send them off to their own settlement?

they will have a synth component on them

after this happened i went back to a save over 3 RT hours back and sneak killed one of them and the synth component was on their corpse

so i could save game, kill all settlers at settlement X, find out whos synth (if any) by finding components on their corpse, then re load and send said settlers to their own settlement

You could build a special settlement just for synths..if you catch by drift.

This reminds me of a dream I had the other night. I was feeling a bit restless and anxious in general and I had been playing Fallout 4 before sleeping. During that play session, my happiness level in sanctuary mysteriously dropped from 82% to 55%. I checked everything there and nothing was in disrepair and there was plenty of food, water, defense, etc. Happiness started going back up again and eventually got back to where it was.

However, in my dream, I "knew" that Sanctuary's happiness had gone down because they found out their settlement was infiltrated by stealth synths, but they didn't know who the synths were, so they became anxious and suspicious of each other until my character came and made them all feel better again. After I woke up, I had to go in game to check on my settlement to make sure everything was still okay there.

no i want to SAVE the synth infiltrator because they are one of my settlers, i dont want to lose my settlers i didnt want to spend around 5 real time days of my 7.5 real time day save file on settlements building them up, designing them, shifting settlers around to them trying to arrange perfect little townships, clothe them feed them arm and armour them, assign them jobs, sit and have a drink with them, hang out with them, give them affectionate nicknames in my head etc etc etc just to have the game turn around and say oh time to die and there is nothing you can do about it haha

if they die in battle i failed to defend them

if they disappear through the kidnapping event its because i failed to rescue them

but this as far as i can see is just a middle finger as there seems to be no way to stop this and/or save them?

so that does work? you can have a settlement thats just all the synths that infiltrate and they will never trigger?

ifso then im gonna send them to covenant, will amuse me with the irony

So you go to trade with them and you see the component? I've been switching all my settlers to Road Leathers so I know who I've assigned and who I haven't, but I haven't seen that in anyone's inventory yet. Does this only happen after the Institute is gone, and you allowed an evacuation, or does it happen at any time?

Only when the settlers are dead. The synth component spawns on their corpse.

Didn't know that there were Synth settlers.

Ok ... then how do you know they are a synth while they are alive so you can move them to another settlement?

Kill them, check inventory for Synth Component. Reload. Send those who had the Component to another settlement.

Spawning a synth component is random. If you kill a settler who has it and then reload chances are he doesn't have the synth component again. It's a triggered(by choice or glitch) event that can't be avoided. The loading screen mentions that settlers fear one if their own may be infiltrated/ replaced by synths

Trigger what exactly? If I have synth settlers they have never done anything that caused me any trouble. So that leaves me wondering what exactly the trigger?

The problem being, the game hardly recognizes that the attack has been a single person. If you arrive to find a dead settler with Synth components, you can brace yourself for a failed to defend with all the consequences. Something just doesn't trigger in these instances.

I resurrect the Synth using the Console, but I agree this is a Known Issue that Bethesda needs to Patch. I hate repairing damaged Settlements, and have gotten somewhat Paranoid about monitoring the Misc Quests when playing.

The synth component is not in their inventory, it is on their corpse. Basically, they have to be dead for you to detect them.

The synth settlers are NOT one of your settlers. They are the Institute infiltrators. They are there to kill your settlers.

One time (I assume this was a Bug) I had a settler who was all acting trippy on the main path at sanctuary with his gun out going back and forth and wouldn't do the task I assigned him to. When i went to trade him I saw a synth component and an institute pistol on him, out of curiosity I left him be to see what happened... nothing really. I came back at a later time when I had a defend alert and the turrets gunned him down and the bug where the defend settlement could never complete.

Curious what would have happened if you removed the synth component.