Alot of people (myself included) are reporting exactly the same thing - it’s faulty left trackpad haptics.

Some people have fixed it by removing the trackpad and remounting it with less pressure but that hasn’t worked for some people.

I’ve just returned my deck with faulty left trackpad haptics and ordered a new one

https://www.reddit.com/r/SteamDeck/s/QluwXzxfuz

If it said 3-5 days estimated when you ordered, that’s your estimate. The new estimate on the site is because new orders are now going into later batches. There’s only so many orders their distributor can process per day.