Firebase手机认证收不到SMS验证码，onCodeSent方法未触发求助

I integrated Firebase Phone Authentication into my app, and it worked perfectly until last night. Suddenly, I stopped receiving the SMS verification code—even though the authentication process seems to run smoothly, the text never arrives.

• I tested with other phone numbers and did receive the SMS, but those aren't my devices so I can't complete the authentication flow.
• I checked Firebase's official docs and saw the SMS sending limit is 500 messages per IP per hour, but I only tested 34 times in a day—way below the cap.

The critical issue is that my login flow relies entirely on the onCodeSent() method: this method triggers when the verification SMS is sent, which displays a modal for code input. Once the modal is closed, the login completes. Since I'm not receiving the SMS, onCodeSent() never fires, the modal doesn't show up, and the entire login process is stuck.

I'm a new Stack Overflow user—if I posted this question in the wrong place, please let me know where it should go instead.

内容的提问来源于stack exchange，提问作者Hime-sama