Did you hit/play around with it? That could make the healing period longer.
If you wrote ndef to it you probably didn’t brick it and glassies don’t fail very often so the most likely is a pocket of blood or swelling or something like that.
Sounds good, I don’t think you can brick it by doing that. I think the best thing you can do is to avoid disturbing the implant location too muche and wait a week or so for any inflammation to go away. Btw how deep is it? Can you see it’s shape through the skin?
You really can’t brick the xSIID unless you authenticate first, then change some of the config data in the last pages of the first sector (first 1kb). What you can do is mess up the NDEF record in certain ways that make it hard for iPhone and in some cases also Android to read or so anything with it… but you can fix these types of issues, generally speaking. For more info on this, check out;
When it comes to the xSIID lighting up but not reading, the bare minimum I can tell you is that the chip and antenna are receiving power from the phone. The LED gets power from the chip’s power harvesting outputs, so there is no functional problem with the chip or antenna. This is a coupling / performance issue, or a fixable issue with memory configuration.
I would try using the Dangerous Things Support Tool to try to write a blank NDEF record to the xSIID;