Apple Pay not working - NFC problem?

Hi there! I have been using my iPhone to pay contactless for over the half a year. 2 months ago, I had to send my iPhone to the service center (with audio problems) and since that time, I can't pay contactless using my iPhone :( I've tried restarting the phone, adding the cards repeatedly, factory reset but nothing changed.

When I need to pay at checkout through terminal, it can't even register that I put my iPhone next to it.

Do anybody knows what may be the problem?

Thank you in advance,

Giacobbeem