It could be the NFC tags that you got, I watched a video by one of the guys who used to be on the workflow team and he said not all NFC tags work as good as others. He tested a bunch out and gave his recommendations.
https://www.matthewcassinelli.com/nfc-tags-siri-shortcuts/
Also he does YouTube videos, they are really informative!
The tags I got- https://www.amazon.com/gp/product/B075CKHH8R/?tag=mjc03-20
Matt’s video about nfc tags - https://www.youtube.com/watch?v=QF1-YCZoT4U
His YouTube channel - https://www.youtube.com/channel/UCdtDUhV2qYOp6D7XuviDOKg
Bought these a couple years ago. They support NTAG-215 which is conveniently the same programming as Nintendo Amiibo characters/cards. Only used about a dozen of them so far, but they work great for triggering shortcuts.