That error is coming from some other app that’s reading or intercepting the NDEF record - it’s not the Shell app, or anything except TagInfo. I suspect this might be because there’s two ways of registering to read NFC tags - saying “i want these” to android or forcing a reader mode in a different way. I’d say TagInfo does the second type, taking over read mode.
See if you can work out what app is making that “invalid tag” box. See how it’s popping up OVER the other app?