Hi @Betty0707 and @Zhan9nan
Welcome to the community.
You can have a look to see if there are any current known problems or work on the network in your area by entering your post code on our network checker.
You'll see the expected coverage first of all, but there is bit below that letting you know if there are any current problems.
If there are, you can sign up for updates and if there are none, you can report a problem.
Michael
