NFC tag recommendation

Hardware
1

Hi,

I ordered two different sets of NFC tags at Amazon (one which can handle metal surfaces and a set of default stickers) but they work both unreliable as hell with my iPhone 12.
Does anybody have a good recommendation for reliable NFC tags with strong iPhone interconnectivity?
Is there btw any tweak to push the nfc performance of an iPhone at all?

Thanks in advance?

2

The only way to improve them is to get ones with a larger design, the larger the coil the better the induction for it to register.

3

Size is not really important for my applications, I just stick them somewhere to trigger e.g. a door lock opening event.
But I could hardly find any larger tags. They seem all to have a diameter of 25mm.