It sounds like your phone might still be trying to use settings or data from your Chinese SIM card. First, try resetting your network settings. This will remove any configurations from the Chinese SIM. You can do this by going to Settings, then General Management, and selecting Reset, followed by Reset Network Settings.
Next, make sure your phone is set to use the correct SIM card for your region. Go to Settings, then Connections, and SIM Card Manager. Check that the correct SIM card is selected for calls, messages, and data.
If the problem persists, it might be helpful to manually set your phone's network and region. Go to Settings, then Connections, Mobile Networks, and Network Operators. Select your home carrier manually.
For the "unknown number" issue, ensure that your carrier's APN settings are correctly configured. These can typically be found on your carrier's website, and you can enter them manually in Settings, Connections, Mobile Networks, and Access Point Names.
If none of these steps work, contacting your carrier might be necessary to ensure your account is correctly set up for your current location.
