I choose the track which appears correctly and then ‘auto tag’ photos. About 1 in 10 times this works but there is no consistency. Also. many times the photo9s that are tagged are in the incorrect place on the track log. Should I buy an independent gps track logger or am I doing something wrong?
Since the tracks appear to show the correct path in the map module, this certainly sounds like a clock synchronization problem.
For the tracklogs with no photos, or those where the photos are shown in the incorrect place, (1) have you verified that you actually needed to set a time zone offset and, if so, (2) are you certain the offset that you set is correct?
From
Work with the Map Module:
To set the time zone offset:
1. In the Map module, select those photos in the filmstrip that you want to match to the track log.
2. Choose Map > Tracklog > Set Time Zone Offset.
• In the Offset Time Zone dialog, adjust the Offset slider.
3. Click OK.
Note:
The Offset Time Zone dialog displays the range of capture times of the selected photos and the range of times in the track log. Adjust the Offset slider to a value where these ranges overlap each other.
Note:
If the Offset slider value does not seem to match the track log timezone and the timezone of your photos, Lightroom indicates it by highlighting the track log time in red. However, you can still set that Offset value.
Your iPhone apps may emit positions on the tracklog that are somewhat less accurate than a high-quality dedicated GPS logger, but there's no reason why they shouldn't work.
The GPX file format is readable text. You might try looking at one of your GPX files to determine whether the position timestamps—adjusted, as necessary, for the correct offset—are consistent with the timestamps recorded in the corresponding image metadata.
