Navigate to /usr/lib/enigma2/python/Plugins/SystemPlugins/AutoBouquetsMaker/custom
Copy the file called EXAMPLE_hd_terrestrial_uk_freeview_CustomLCN.xml to your PC
Make a copy and name it "unchanged". Do not touch this, hence the name. Upload it here. You can do that before you do next step
Using a linux compatible editor like notepad++, edit the file so that the non-working channels are remaining. Attach the file here.