Even though you are outside of the warranty period, I would contact them and push the issue. It can't hurt.
This same thing, with the bit of plastic that connects to the band falling off, happened to me, and they did not repair it. They just sent me a new one. I lucked out when it happened, because it was last year mid-February a week before my warranty expired on Feb 21,2022.
The one I have now is almost exactly a year old, but obviously not on a warranty because I'm assuming it falls under the warranty for the original one. So now the battery lasts less than 24 hours. I'm beginning to wonder if these aren't being manufactured to fall apart right after warranty! I laugh when I say that, but it's not an unheard of practice by companies.
Whatever is going on, there's a real issue with the products. I'm thrilled with the service Fitbit provides, but I'm not thrilled with serious degrade of quality. I've been an extremely loyal Fitbit user for over a decade now, and there is no good reason devices should now need to be replaced every year (or two, as in your case). I'm going to start seriously looking around to see if other brands are more reliable 😞
