Thanks for your help but,
Same problem. Made the try. Look at the sliders: I can zoom up max to 100 m with Detail on zero:
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When I set Detail one point it looks like this:
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Cleaned my caches; installed Basecamp again, etc.
Well, of course I can make my tracks with zoom 100/no details.
The map works excellent in my GPS with all the details.
But I stay curious about this problem in Basecamp.