When I looked at my DF on the 4 possible layouts on vivoactive5 in the simulator I noticed that on "3 Fields" and "4 Fields" the fields are not centered. They are off to the right. I think the reason is that in simulator.json some the width values of the fields in these 2 layouts are 416 instead of 390 and 207 instead of 195:
{ "drawBorders": false, "fields": [ { "data": { "font": "numberThaiHot", "justification": "center", "width": 406, "x": 195, "y": 128 }, "label": { "font": "xtiny", "justification": "center", "x": 197, "y": 41 }, "labelDisabled": false, "location": { "height": 129, "width": 416, // correct: 390 "x": 0, "y": 0 }, "obscurity": [ "left", "top", "right" ] }, { "data": { "font": "numberThaiHot", "justification": "center", "width": 406, "x": 195, "y": 123 }, "label": { "font": "xtiny", "justification": "center", "x": 197, "y": 30 }, "labelDisabled": false, "location": { "height": 128, "width": 416, // correct: 390 "x": 0, "y": 131 }, "obscurity": [ "left", "right" ] }, { "data": { "font": "numberHot", "justification": "center", "width": 406, "x": 194, "y": 112 }, "label": { "font": "xtiny", "justification": "center", "x": 196, "y": 41 }, "labelDisabled": false, "location": { "height": 129, "width": 416, // correct: 390 "x": 0, "y": 261 }, "obscurity": [ "left", "right", "bottom" ] } ], "name": "3 Fields" }, { "drawBorders": false, "fields": [ { "data": { "font": "numberThaiHot", "justification": "center", "width": 406, "x": 195, "y": 128 }, "label": { "font": "xtiny", "justification": "center", "x": 197, "y": 41 }, "labelDisabled": false, "location": { "height": 129, "width": 416, // correct: 390 "x": 0, "y": 0 }, "obscurity": [ "left", "top", "right" ] }, { "data": { "font": "simExtNumber1", "justification": "center", "width": 197, "x": 93, "y": 107 }, "label": { "font": "xtiny", "justification": "center", "x": 95, "y": 33 }, "labelDisabled": false, "location": { "height": 128, "width": 207, // correct: 195 "x": 0, "y": 139 }, "obscurity": [ "left" ] }, { "data": { "font": "simExtNumber1", "justification": "center", "width": 197, "x": 80, "y": 107 }, "label": { "font": "xtiny", "justification": "center", "x": 82, "y": 33 }, "labelDisabled": false, "location": { "height": 128, "width": 207, // correct: 195 "x": 209, "y": 139 }, "obscurity": [ "right" ] }, { "data": { "font": "numberHot", "justification": "center", "width": 406, "x": 194, "y": 95 }, "label": { "font": "xtiny", "justification": "center", "x": 196, "y": 24 }, "labelDisabled": false, "location": { "height": 129, "width": 416, // correct: 390 "x": 0, "y": 278 }, "obscurity": [ "left", "right", "bottom" ] } ], "name": "4 Fields" }