Thanks for the detailed report.
I like the speed limit “feature” in the images! 
If device remains the same, can only think the new Google location service in Kurviger 1.9.3 if reports erroneous things, though have not seen so far such behavior. It’s supposed to be better than Android’s native one…
Now I’m thinking if the new location service option should use by default the Android service and Google’s one would be optional, after all theirs is black box without internal knowledge and further tuning.