There is a limited number of automatic hotspots you can connect to in poor coverage areas typically listed as EE WiFi-Auto. This is known as WiFi Coverage Boost and included for PAYG and Pay Monthly customers under certain criteria listed here: (as well as the instructions to set this up as it is not automatic on all devices)
https://ee.co.uk/help/mobile/manage-use/using-phone-features/how-do-i-access-wifi-coverage-boost
This is separate to the normal EE WIFI hotspots you may see which are only available by buying a voucher or being a BT or New EE Home Broadband customer.
