Try this please.
Go to settings, then scroll to Backup and Reset.
Then tap on Reset.
That will reset your network settings.
Then check for normal operation.
Okay, go to settings, then choose mobile network, then make sure global is enabled.
If you can’t get a signal where you normally would, there could be an issue with the network. However there also be a problem with your device. So we suggest you follow this checklist if you’re having trouble
Check the expected 4G, 3G and 2G coverage in your location on the EE coverage checker. Although it’s only a guide, it can tell you whether you should expect to get coverage in a particular location.
By testing your SIM card in another EE handset you can quickly establish if the issue is directly related to your phone or not.
If your SIM doesn’t work in another EE handset, we would then suggest testing a different EE SIM card into your device. If the other SIM card does work with your phone you can order a new replacement SIM card online. <<click blue link.