NFC Tag is not working anymore?

I ordered with new NFC tags. Wanted to try this today and describe it with the app "NFCTools". But this has not found my phone (Huawei P10 lite). NFC was on! Then restarted the phone and then I could a day with a text file described and read again (both took but a little). But since then I have the problem again that my phone does not find the tags. Habs tried several times with a reboot of the phone and also tried different apps. But nothing works anymore. Does anyone have an idea what it is?

Install "NXP Tag Info" if you have not tried them yet.

Even if you accidentally locked them, the phone should be able to read them. As a joke, I've locked one of my tags (which I've tested for) to make screenshots, what it looks like (which you'd better not do with an implant) Just picked out the day, NFC Tools Pro and NXP Tag Info read it perfect

Which tags are there: NTAG213 or NTAG216, mifare desfire, mifare classic, i-code, …

Let a friend try if he can read the tags with his cell phone. If it doesn't work, then the tags surely have something.