How to fix brand new airtags that don't update its location?

hello,

my airtags are a week or so old. Bought it for my flight to Korea. Was working up until I left Toronto airport. Now even though the airtags are literally right next to me it says in Find My "Last Seen 3 days ago". So I thought okay maybe bad luck and battery is dead...nope...I opened one and immediately the battery made the ping sound. So i reset the tag, re-added it to my phone, and now it just says "no location found" (the rest still say last seen 3 days ago).

Didn't work when I tried to share its location with my local friend.

Not sure what to do. I need these air tags to ensure I don't leave anything behind as I'm travelling across Korea. These weren't cheap either so I am pretty ****** off that I bought a pack of 4, and they're useless. I can't return them either since I'm not in Toronto and won't be for a couple months.

Hoping someone here has an idea of what I can do to fix this. I'm downloading latest software update right now but I have my doubts it'll change anything. *Edit* no, it did nothing to fix this issue.

thanks for your time