Unable to read custom NFC tags on iOS 16.0 (iPhone 13 Pro Max)

Hello, I'm trying to read custom NFC (13.56mhz) tags with my iPhone using an NFC app, but none of them seem to be working (I've tried the three most popular NFC apps). I am writing text to these tags using a RC522 connected to a Raspberry Pi.

I know that my scanner is working because I can read and write text to tags. I know NFC on the iPhone is working because the scanner also detected the signal when I opened and activated Apple Pay. Besides that, I am using known-good tags (such as a hotel room key) that also work with my scanner but not my iPhone.

Has anyone else encountered this issue? Is there a solution?

Thanks.