@BOT_jasper 

Hi

You may reset the router and then check.

If it still shows connecting, please go to Advanced->Dial-up->Dial-up Settings page, check the current APN profile settings is correct or not, if not, you could select other profile from the list if available, or create profile manually and enter APN etc. manually.

Note: If you are not sure about the APN profile settings, please contact the ISP of your SIM card to confirm it.