Record the working pair first
Before adding a second source, note which configuration supplies the working channels and which XMLTV address belongs to it. Preserve the current configuration privately. A playlist and programme guide can be updated independently, so copying a familiar guide address into every source may produce plausible-looking but incorrect schedules.
Use local labels that distinguish the providers or purposes without exposing credentials. A label such as Living room test is easier to discuss than an entire authenticated URL. Never post the full configuration when a redacted field description will show the relevant format.
Use a separate add-on configuration
The current project README documents Configure → Add add-on configuration for multiple M3U/XML pairs. Use the controls present in your installed version and keep the second list with its own intended guide. Old screenshots may describe a single-source interface rather than the current configuration model.
Begin with ordinary channel loading before examining the full guide. If the second list does not load, investigate its location or source access first. An empty schedule is a later problem than an unavailable channel inventory.
Compare channel identity rather than display name alone
Pick a channel you can recognise in each source and compare the schedule with the actual programme. If a guide belongs to the wrong feed, the name can look correct while the regional schedule differs. Channel identifiers and mapping matter as well as the words shown in the list.
Keep a wrong programme distinct from an empty guide or a uniform clock offset. Applying a time shift to a mismatched feed can make one entry appear better while leaving the underlying mapping wrong. Record the channel, guide source and time of comparison.
Verify the second source without breaking the first
After the new configuration loads, return to the original source and confirm its channels and guide still behave as expected. This catches an accidental edit to the wrong configuration. Use one identifiable example from each rather than a large screenshot of every account.
A successful pair does not prove that catch-up, recording or every stream is supported. Report the Kodi version, add-on version and first failing stage if help is needed. Keep the application’s capability separate from each provider’s actual account features.