I shouldn't think it's the rackets causing issues if you have had them since December with no problems. Sounds more like form than anything. Perhaps you are snatching at the shuttle, a bit too eager to hit it rather than flowing smoothly? It is hard to say what causes this sort of thing but now that you are thinking about it, it will probably keep up or even get worse for a while. As you are almost putting the thought of misshitting the shuttle in to your head if that makes sense? Best thing I could suggest is to just play naturally and try to put it out of your mind. Maybe give yourself a target to keep your mind off it, like making your serves the best they can possibly be, really concentrate on them and make good serves your focus instead. Anyway good luck and hope things get back to normal soon. 

Whilst I'd agree with all of the above, I will throw a spanner in the works and share this with you.

I had a set of Fleet rackets (Yehlex network), they served me well. I suffered a bad wrist injury whilst building a trampoline (don't ask!).

Around this time I was looking for a more head light racket as mainly play doubles these days so I brought a pair of Browning rackets (I had tried this model out so I knew what I was getting). I noticed that you have to hit the shuttle differently to generate more power for a smash. I have used the Browning rackets for nearly two seasons. I've been struggling for any power in my smashes for a while and now my wrist is much better than it was, I dug out my Fleet rackets and used them again. Whilst I'm still trying to get used to the more head heavy-ness (it's not a word, I know!), my smashes have been MUCH better and also my net control.

I think my problem is, I see things happening before they have happened, and I swing before it's happened. I do everything too fast and with a lighter racket, this caused me problems with mis-hits and what not. I'm finding that my Fleet rackets give me a better feel for the shuttle and my timing is a bit better. So all in all, maybe head light rackets aren't for me. It's taken me too long to get to this stage as it was a mixture of just hoping that I'd get “used to it” in time or whether it's just me not being good enough.

So whilst it's easy to “blame your tools”, picking the right tools for YOU is important and can help massively. I know after all (although I won't admit it in person ), that I'm no Lin Dan and therefore could wipe the floor with any old racket 

Just my 2p!