I don't know if it is some game mechanic that is purposely made but I had played this since the start with my first character and was lvl 25 and had Piper as my companion and she was ace. She did almost all of the time what I ordered her to with regards to 'Go There' but mostly to pick things up she picked everything up and searched bodies at a click and even tight spots like behind diner counters she would find a way to collect stuff I was telling her to.

So then my XB1 downloaded 1.3 and so I thought "I actually fancy a second play now that I am familiar with this installment and the patch is in place"

So fired up a new go on 1.3 last night (And I am NOT totally blaming the patch but for my case it seems too much of a coincidence) and started afresh and finished the night as I had just got her as my companion and my first PA etc and ready to head out

........ She is annoying, useless and frankly ruining the aspect now of this game of having a companion - she makes the earlier companions of old like the FO3 Dogmeat, Skyrims Faendal etc look like they have the NPC AI of Stephen Hawking in comparison!!

# I come across some enemies - she is walking behind me in the distance

# I ask her to pick something up (or loot the body) and she she tells me for the thousandth time that's the plan, but despite my previous (Monday night) self had an immunity to her walkytalky lines as she was so good, now it annoys me as she just tells me that she can't get to the item even though a deck chair is her way and she is walking against it rather then just WALKING AROUND IT

# I ask her to pick something up (or loot the body) and she walks over but does nothing

# I ask her to pick something up she does the same but I have to wait several seconds for her to pick the item up (or loot the body)

# The above scenarios finally lead to her actually picking an item up \ looting body

And I have tested this out with a mix of weapons armor junk on a landing pad so nice and clear and dropped a ton of gear and only a third of the time would I be able to get her to pick the stuff up.

# She walks away and disappears and decides to sit down constantly whenever seating is available.

Like I say she was a gem a few nights ago on my first playthrough from game release, but then 1.3 and new playthrough - she is as useful as a chocolate fireguard.

Has anyone else noticed the Companion AI turn into a lemming since 1.3?? Should I just use her as cannon fodder now??

The behavior you are seeing isn't substantially different than how they all act, and have acted, since the game was first released. In fact, imo, Piper is the least good at following, tends to lag farther behind than the others on even pavement running in a straight line and I've seen her engage in serious, extended combat with a wall.

That sitting down behavior is my personal pet peeve. They are so lazy! Every chance the get they sit down.

When Piper is walking slowly behind, it means that she's ready for her quest stage talk. I saw this last night and remembered that in Skyrim a follower that can be your steward with the Hearthfire DLC will do the same thing when approaching one of your homestead. I walked up to Piper and initiated the conversation and she did start the quest related conversation thread.

I think all companions act like this haha

Yeah, they may do that, although it isn't always noticeable. They'll say something to you to start the convo and if you ignore them they start following again with no problem. I don't know why Piper lags more. I mean, it happens to all of them, but usually Danse, etc are falling behind because I'm sprinting or going up difficult terrain a lot faster than they do. Although if they've managed to sit down somewhere or wandered especially far away it can take a while for them to catch up. But Piper lags when I'm running straight down a road. I think she's as good a companion as any of the others, the lagging isn't so much worse than the others that it would prevent me from having her around if I liked her, it's just something she did when following me on two different characters so it stood out.