Hi, User 11887982978107664736
Welcome to Google Maps Community Support Forum & thanks for your post.
First, I want to make a small request.
Can you adopt an intelligible screen name instead of a series of random numbers?
That helps to maintain consistency while replying to the same post in the future.
Now my findings are, Maps doesn't retain the unit setting. The moment you close navigation & look for the next, Maps will default to the distance units in vogue in that specific region.
The region settings in search or user profile don't make any difference.
The user has to select the desired unit while looking for the directions.
Nevertheless, you can suggest the feature through the Help & feedback route.
Here is a link explaining how to do so.
Once there are a sufficient number of users requesting the same feature, that may become available later on.
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PS: In this peer support forum, volunteers answer the queries.
The volunteers are users of Google Maps like anyone & do not have any special privileges to make changes in Maps.
Google employees or representatives aren't reading the posts usually.