When I use a custom field OSM with a default lat/lon and add the post first, save, edit and change the location then the zoom = 1 (the whole world) with one marker. Also when adding location address it won't zoom in. The only way is to click 20 times on the + icon. See my video https://videouitleg.ceescoenen.nl/recordings/3EKjqpaUcprwf51tKSr8
That happens when the zoom value is not added to the default value. Please add the zoom value along with the lat/long and check the issue again. For example: 21.1159071,107.8167312,10
.
