An EPG can contain correct programmes yet display beside the wrong channel when playlist and XMLTV identifiers do not match.
The identifiers on both sides
An M3U channel may declare tvg-id, while an XMLTV document defines a channel id and programme entries that reference it. The player joins those values. Names that look identical to a person can differ by case, spacing, punctuation, region, or HD suffix, so name-based guessing is fragile.
Why mappings fail
Providers may rename channels, split regional editions, replace SD with HD, or supply multiple guide sources with overlapping IDs. A stale cached EPG can survive after a correct edit. Time-zone errors are separate: a successfully mapped programme can still appear one hour early, so identity and clock diagnosis should not be mixed.
A controlled correction
Choose one channel, compare its exact playlist tvg-id with the XMLTV channel id, and update the mapping using the player’s supported method. Refresh or clear only the guide cache, then verify current and next programmes against the broadcaster schedule. Repeat in small batches and keep a mapping note for future lineup changes.
- Compare IDs character for character
- Test one regional variant at a time
- Refresh guide data after mapping changes
Conclusion
Stable, exact IDs create reliable guide joins; names are useful labels but poor database keys.