I am not sure if this is an Android bug, a Windows bug, or a Navigator bug. It is surely an interaction of the 3.
I found 12 log files in the Tools of Navigator 2.0.33
I find 12 log files using ESFileExplorer in
android/data/com.mapfactor.navigator/files/navigator/nmea
But if I connect my Nexus 5X running 6.0.1 to my Windows 7 PC and look with explorer, I only see 3 files.
The 3 files are random from 2 months ago, 1 week ago, and yesterday - so it is not as if an update has made a difference. on a certain date.
The other 9 files are invisible. Show hidden files is on.
Not a big problem - I copied them to /Download using ESFileExplorer and then they become visible and I can move them to the PC to add to my travel history.
But it is a mystery as to why some files are visible and others aren't.
It is not related to size. There are 2 large visible ones and one small one. All the files have good data once I copied them to a different folder.
Obviously not a high priority issue, but bringing it to your attention. If I can help you resolve it with further information, just ask.
Peter