Answer that before changing a single setting, because the two symptoms have almost nothing in common. A grid that is empty across all 54,000+ channels means the player never finished fetching the guide file: a wrong address, expired credentials, a compressed file it could not unpack, or a download that timed out into an empty grid rather than an error message. A grid that is populated nearly everywhere but blank on a dozen channels is an identifier problem, because rows are matched by tvg-id and not by the channel name you read on screen. One missing id blanks that row while the stream behind it plays normally. Scoping takes ten seconds and it decides which half of this page applies to you.

1. 1Blank everywhere: the file or the address
2. 2Blank on a few: id matching
3. 3Uniformly shifted: a double time offset

A playlist refresh replaces the channel objects the player was holding, and every manual mapping you made was attached to the old ones. Stream addresses come back, guide links do not. Players also cache guide data on their own timer, often once or twice a day, so the grid can stay blank for hours after the channel list is healthy again. Force a guide update instead of waiting for that timer, then re-check only the channels you had mapped by hand. Keep any mapping notes outside the app. Reapplying six lines after an update is a two-minute job, and rebuilding forty from memory is the reason people give up on the guide entirely.

1. 1Force update, then clear cache, in that order
2. 2Re-check manual mappings after every playlist change

Guide files carry UTC timestamps plus their own offset, and most players read that offset and render local time without help. Trouble starts when a manual time shift is added on top, because the correction lands twice and the whole grid slides by that amount, usually a clean hour. The tell is uniformity: an identifier mismatch never produces a tidy, identical error on every channel. Set the player's guide time shift back to zero, let the file's own offset stand, and only add a shift if the grid is still wrong afterward, and only by the difference you can actually see. Daylight-saving weekends produce the same symptom for a day or two on sources that hardcode an offset.

1. 1Same error on every channel means an offset, not a mismatch
2. 2Set the shift to zero before adding one

No, and confusing the two wastes whole evenings. Guide data is a separate file fetched on a separate schedule from video segments. If channels play while the grid is empty, your line, your credentials and your bandwidth are all fine, and reinstalling the app to fix video you never lost is wasted effort. The reverse holds too: a full, correct guide sitting over channels that will not start is a stream fault. Test it by switching away to another channel and switching back. Recovery on switch-back means the session stalled rather than your connection failing, which points at the server side, not at your router or your Wi-Fi.

1. 1Guide empty, video fine: leave the stream settings alone
2. 2Switch-away-and-back is the cheapest server-versus-local test

Some of it, and pages that pretend otherwise send readers in circles. Guide files are generated on the service side. If generation fails, or the window only runs a few hours ahead, no app setting extends it, and a grid that goes stale during peak hours is often the same infrastructure under load. That makes it a fair question to ask any service before you pay: what uptime do you publish, and how far ahead does the guide run. We publish 99.99% uptime, which is roughly 53 minutes of downtime across a year, and a $5 24-hour trial exists so you can watch a guide populate on your own hardware first.

1. 1Ask what uptime a service publishes, not whether it is stable
2. 2Test the guide on your own device before paying for a term