Migration is not a big deal really… it can move around under your skin but as long as it was placed into the fascia layer between dermis and muscle, there is very little chance of it moving into muscle or joints or anything like that. It might scoot to an area overtop a joint or into a spot that isn’t ideal, but barring some really unlikely circumstances, it won’t lodge itself into anywhere important.
The part of your OP I didn’t really notice before was this bit: “Sometimes, when I go to bed and wake in the morning, its traveled back to the injection site, I have to push it back.” - This is normal and part of healing… implants can sometime scoot back the direction they came to rest right under the injection spot. I think “pushing it back” caused the darn thing to never settle down. The initial reaction your body has is to heal around the wound… it’s what helps encapsulate the tag, but now that the wound is basically healed up, all the pushing and fiddling kept the tag from being encapsulated… it’s basically loose in your body and it’s not able to illicit enough of a response from your immune system to warrant any collagen growth.
It’s part of the training I typically give partners to instruct people to not fiddle with the implant… don’t push on it or move it around under the skin… however it settles is how it settles… I think this is the problem here… you no longer have enough of a wound response to get your body to lock that thing down.
I think removal and re-installation with a 10g needle and taper is the best course of action. The tag can be autoclaved, but test before implanting by putting sterile gauze over and reading with a phone.