Thought it should add guide data to the end of what was already fetched. It does, but leaves a gap.
If you got the daily guide update this morning around 9:00 AM you would have guide data going out to Feb 13 9:00 AM.
Fetch Guide Updates should then fetch new data starting at Feb 13 9:00 AM.
I'm seeing it start fetching at Feb 13 12:30 PM, leaving a gap from 9:00AM to 12:30 PM.
Should be easy to duplicate, here's relevant portions of the log.
This morning daily update fetched 6hr blocks from 2022-01-28 9:00AM to 2022-02-13 9:00AM
2022/01/28 09:11:00.008794 [DVR] Fetching guide data for 144 stations in X-TVE @ 2022-01-28 9:00AM
...
2022/01/28 09:15:07.963647 [DVR] Fetching guide data for 144 stations in X-TVE @ 2022-02-13 3:00AM
Tonight I ran Fetch Guide Updates which only fetched the 6hrs from 2022-02-13 12:30PM to 2022-02-13 18:30PM
2022/01/28 18:56:40.655324 [DVR] Fetching guide data for 144 stations in X-TVE @ 2022-02-13 12:30PM