Hi Killerkickan,
I wanted to post parts of our conversation publicly so others can benefit from the progress of our troubleshooting.
Amal and I have been discussing your case this weekend.
To help get closer to a resolution,
please download the "Tag Info’ app by NXP for the iPhone.
Scan your xM1+ tag info. Within the app there should be a share icon, that you can tap to share via email the report directly to me and I’ll review the report with Amal.
Unfortunately, unlike the large body of NFC tag specifications, the Mifare Classic does not have broad specifications. NXP did eventually create a sudo specification for the Mifare Classic that does work with some phones that have the NXP reader chips.
Just to ensure you are aware, we have authorized, and Patrick from Digiwell has confirmed, he has sent the xLED field tester to you.
My best,
MDanger