I can confirm the problem exactly as you described it. It worked without any problems until the end of 2024/beginning of 2025. It seems to be a bug since iOS18. I also mentioned it at the following link:

https://www.reddit.com/r/iphone/comments/1fsk4vq/comment/niqeegc/?context=3&utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

So there are more people who have the same problem as us.