Go to Configuration -> Channel/EPG -> EPG Grabber Modules and enable the "EIT DVB Grabber" and "UK: Freeview" modules. Leave the Priority numbers as-is.
Go to Configuration -> Channel/EPG -> EPG Grabber and check that the "Over-the-air CRON Multi-line" box has its default value of "4 2 *" which will trigger an EPG scan at 02:04 every day (assuming your Pi is powered up at that time!).
Go to Configuration -> Channel/EPG -> Channels and check that all of your channels have "Automatically map EPG source" ticked.
Go to Configuration -> DVB Inputs -> Muxes and check all muxes have either "Auto-detected" or "Enabled (auto)" in the "EPG Scan" column.