Before posting a guide problem, choose a programme with a schedule you can check on the broadcaster’s site. Record the exact channel edition, the time in the guide and the expected time with your local time zone. Check a second unrelated channel. A consistent shift across both rows gives you a clock or offset question. A single incorrect row gives you a feed or channel mapping question.
If you can still play the channel, say so. Add the last successful guide refresh and your player version. If tomorrow’s guide ends at a particular hour, give the last entry on two channels. That helps separate a source window from a local problem.
Keep private guide or playlist links out of the post. A cropped view of one row is enough to start the discussion.