What happened when I had my retainer and after, my teeth wouldn't bite together? I was able to bite all the way back when I first removed my retainer, but now I've been wearing a retainer for 3 months

What happened when I had my retainer and after, my teeth wouldn't bite together? I was able to bite all the way back when I first removed my retainer, but now I've been wearing a retainer for 3 months and after removing it, I'm only able to bite my teeth. Analysis:

Because the retainer is covered around the teeth, wearing a retainer, the back teeth bite difficult, so, in addition to eating to go down, usually should also go down, teeth bite hard a few times, and then put on.

Guidance:

Now the front teeth bite down to, the back teeth can not bite down, to re-correct. It's not the retainer that's the problem, it's the way you use it and the technique you haven't mastered.